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The influence of coordination compounds on spin chemical processes in irradiated hydrocarbons

Published in Doklady Physical Chemistry, 2012

In this paper, we studied the effect of a coordination compound introduced into the sample on the MARY spectrum of a radical ion pair with known properties

Recommended citation: Sergey N.V., Stass D.V., Burdukov A.B., Melnikov A.R., Molin Y.N. "The influence of coordination compounds on spin chemical processes in irradiated hydrocarbons" Dokl. Phys. Chem. 2012. 442(1). P. 12-15.
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A Low-Field Magnetically Affected Reaction Yield (MARY) Spectrometer with Spectral Fluorescence Resolution

Published in Applied Magnetic Resonance, 2012

In this paper, a novel spectrometer for low-field studies in magnetically affected reaction yield (MARY) spectroscopy with fluorescence detection is described

Recommended citation: Kalneus E.V., Melnikov A.R., Korolev V.V., Ivannikov V.I., Stass D.V. "A Low-Field Magnetically Affected Reaction Yield (MARY) Spectrometer with Spectral Fluorescence Resolution" Appl. Magn. Res. 2013. 44(1). P. 81-96.
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Registration of radical anions of Al, Ga, In tris-8-oxyquinolinates by magnetosensitive and spectrally resolved recombination luminescence in benzene solutions

Published in Chemical Physics Letters, 2012

In this paper, we studied the formation and recombination of transient radical anions of Al, Ga, and In tris-8-oxyquinolinates

Recommended citation: Sergey N.V., Verkhovlyuk V.N., Kalneus E.V., Korolev V.V., Melnikov A.R., Burdukov A.B., Stass D.V., Molin Y.N. "Registration of radical anions of Al, Ga, In tris-8-oxyquinolinates by magnetosensitive and spectrally resolved recombination luminescence in benzene solutions" Chem. Phys. Lett. 2012. 442. P. 32-37.
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Exciplex formation upon recombination of radiation-generated radical ion pairs in nonpolar solutions

Published in Doklady Physical Chemistry, 2013

In this work, we studied photo and radiation induced luminescence spectra of solutions of some donor–acceptor systems widely used in the radiation spin chemistry experiments, in particular, anthracene-DMA, p-terphenyl-DMA, and similar systems

Recommended citation: Melnikov A.R., Kalneus E.V., Korolev V.V., Dranov I.G., Stass D.V. "Exciplex formation upon recombination of radiation-generated radical ion pairs in nonpolar solutions" Dokl. Phys. Chem. 2013. 452(2). P. 257-260.
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Stimulation of luminescence of mycelium of luminous fungus Neonothopanus nambi by ionizing radiation

Published in Luminescence, 2014

In this work, we report the effect of X-irradiation on the luminescence of fungus Neonothopanus nambi. Application of X-rays does not change the emission spectrum, but after approximately 20 min of continuous irradiation, light production from unsupported mycelium starts growing

Recommended citation: Kobzeva T.V., Melnikov A.R., Karogodina T.Y., Zikirin S.B., Stass D.V., Molin Y.N., Rodicheva E.K., Medvedeva S.E., Puzyr A.P., Burov A.A., Bondar V.S., Gitelson J.I. "Stimulation of luminescence of mycelium of luminous fungus Neonothopanus nambi by ionizing radiation" Luminescence. 2014. 29(7). P. 703-710.
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Highly efficient exciplex formation via radical ion pair recombination in X-irradiated alkane solutions for luminophores with short fluorescence lifetimes

Published in Photochemical Photobiological Sciences, 2014

In this paper, we shows a possibility of exciplex formation via irreversible recombination of radical ion pairs generated by X-irradiation of alkane solutions of N,N-dimethylaniline with various organic luminophores

Recommended citation: Melnikov A.R., Kalneus E.V., Korolev V.V., Dranov I.G., Kruppa A.I., Stass D.V. "Highly efficient exciplex formation via radical ion pair recombination in X-irradiated alkane solutions for luminophores with short fluorescence lifetimes" Photochem. Photobiol. Sci. 2014. 13(8). P. 1169-1179.
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Effect of ionizing radiation on the luminescence of mycelium of luminous fungus Neonothopanus nambi

Published in Biochemistry, Biophysics and Molecular Biology, 2014

In this paper, we report the effect of X-irradiation on the luminescence of fungus Neonothopanus nambi

Recommended citation: Bondar V.S., Puzyr A.P., Burov A.E., Medvedeva S.E., Rodicheva E.K., Kobzeva T.V., Melnikov A.R., Karogodina T.Y., Zikirin S.B., Stass D.V., Molin Y.N., Gitelson J.I. "Effect of ionizing radiation on the luminescence of mycelium of luminous fungus Neonothopanus nambi" Dokl. Biochem. Biophys. 2015. 460(1). P. 30-33.
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Estimation of the fluorescence lifetime for optically inaccessible exciplexes in nonpolar solutions under ionizing irradiation

Published in Photochemical Photobiological Sciences, 2016

In this paper, we present a simple and universal experimental approach for the estimation of fluorescence lifetimes of X-radiation generated exciplexes

Recommended citation: Melnikov A.R., Kalneus E.V., Korolev V.V., Sherin P.S., Borovkov V.I., Stass D.V. "Estimation of the fluorescence lifetime for optically inaccessible exciplexes in nonpolar solutions under ionizing irradiation" Photochem. Photobiol. Sci. 2016. 15(6). P. 767-778.
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Estimation of the Fraction of Spin-Correlated Radical Ion Pairs in Irradiated Alkanes using Magnetosensitive Recombination Luminescence from Exciplexes Generated upon Recombination of a Probe Pair

Published in Zeitschrift für Physikalische Chemie, 2016

This paper describes the magnitude of magnetic field effects in exciplex emission formed by a novel acceptor-substituted diphenylacetylene and DMA

Recommended citation: Melnikov A.R., Verkhovlyuk V.N., Kalneus E.V., Korolev V.V., Borovkov V.I., Sherin P.S., Davydova M.P., Vasilevsky S.F., Stass D.V. "Estimation of the Fraction of Spin-Correlated Radical Ion Pairs in Irradiated Alkanes using Magnetosensitive Recombination Luminescence from Exciplexes Generated upon Recombination of a Probe Pair" Z. Phys. Chem. 2016. 231(2). P. 239-267.
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A comparative study of optical properties and X-ray induced luminescence of octahedral molybdenum and tungsten cluster complexes

Published in Dalton Transactions, 2017

This paper compares photoluminescence, radiodensity and X-ray induced luminescence properties of eight related octahedral molybdenum and tungsten cluster complexes

Recommended citation: Evtushok D.V., Melnikov A.R., Vorotnikova N.A., Vorotnikov Y.A., Ryadun A.A., Kuratieva N.V., Kozyr K.V., Obedinskaya N.R., Kretov E.I., Novozhilov I.N., Mironov Y.V., Stass D.V., Efremova O.A., Shestopalov M.A. "A comparative study of optical properties and X-ray induced luminescence of octahedral molybdenum and tungsten cluster complexes" Dalton Trans. 2017. 46(35). P. 11738-11747.
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Comparison of exciplex generation under optical and X-ray excitation

Published in The Journal of Chemical Physics, 2017

In this work, we propose a model for describing exciplex formation under X-ray radiation

Recommended citation: Kipriyanov A.A., Melnikov A.R., Stass D.V., Doktorov A.B. "Comparison of exciplex generation under optical and X-ray excitation" J. Chem. Phys. 2017. 147(9). Art. Num. 094102.
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X-ray Generated Recombination Exciplexes of Substituted Diphenylacetylenes with Tertiary Amines: A Versatile Experimental Vehicle for Targeted Creation of Deep-Blue Electroluminescent Systems

Published in The Journal of Physical Chemistry A, 2018

In this work, we show that recombination exciplexes of simple substituted diphenylacetylenes with tertiary amines can be a convenient source of tunable deep-blue emission with possible applications in organic electroluminescent systems

Recommended citation: Melnikov A.R., Davydova M.P., Sherin P.S., Korolev V.V., Stepanov A.A., Kalneus E.V., Benassi E., Vasilevsky S.F., Stass D.V. "X-ray Generated Recombination Exciplexes of Substituted Diphenylacetylenes with Tertiary Amines: A Versatile Experimental Vehicle for Targeted Creation of Deep-Blue Electroluminescent Systems" J. Phys. Chem. A. 2018. 122(5). P. 1235-1252.
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Determination of Hyperfine Coupling Constants of Fluorinated Diphenylacetylene Radical Anions by Magnetic Field-Affected Reaction Yield Spectroscopy

Published in The Journal of Physical Chemistry A, 2018

In this work, the radical anions of two fluorinated diphenylacetylene derivatives with nonequivalent magnetic nuclei and unknown hyperfine coupling constants were investigated by MARY spectroscopy

Recommended citation: Sannikova V.A., Davydova M.P., Sherin P.S., Babenko S.V., Korolev V.V., Stepanov A.A., Nikul’shin, P.V., Kalneus E.V., Vasilevsky S.F., Benassi E., Melnikov A.R. "Determination of Hyperfine Coupling Constants of Fluorinated Diphenylacetylene Radical Anions by Magnetic Field-Affected Reaction Yield Spectroscopy" J. Phys. Chem. A. 2019. 123(2). P. 505-516.
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Water-soluble Re₆-clusters with aromatic phosphine ligands – from synthesis to potential biomedical applications

Published in Inorganic Chemistry Frontiers, 2019

We present the syntheses of two new water-soluble hexarhenium cluster complexes with terminal amphiphilic phosphine ligands, and delineate their photoluminescence and X-ray excited optical luminescence (XEOL) properties

Recommended citation: Ivanov A.A., Konovalov D.I., Pozmogova T.N., Solovieva A.O., Melnikov A.R., Brylev K.A., Kuratieva N.V., Yanshole V.V., Kirakci K., Lang K., Cheltygmasheva S.N., Kitamura N., Shestopalova L.V., Mironov Y.V., Shestopalov M.A. "Water-soluble Re₆-clusters with aromatic phosphine ligands – from synthesis to potential biomedical applications" Inorg. Chem. Front. 2019. 6(4). P. 882-892.
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Electronic Modulation of THz Radiation at NovoFEL: Technical Aspects and Possible Applications

Published in Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2019

In this work, we describe a pulsed mode of radiation generation for the NovoFEL

Recommended citation: Shevchenko O.A., Melnikov A.R., Tararyshkin S.V., Getmanov Y.V., Serednyakov S>S., Bykov E.V., Kubarev V.V., Fedin M.V., Veber S.L. "Electronic Modulation of THz Radiation at NovoFEL: Technical Aspects and Possible Applications" Materials. 2019. 12(19). Art. Num. 3063
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Electronic Modulation of the FEL-Oscillator Radiation Power Driven by ERL

Published in Proceedings of the 39th International Free-Electron Laser Conference, FEL 2019, 2019

In this work, we propose a simple way of fast control of the FEL lasing which is based on periodic phase shift of electron bunches with respect to radiation stored in optical cavity

Recommended citation: Shevchenko O.A., Bykov E.V., Fedin M.V., Getmanov Y.V., Melnikov A.R., Serednyakov S.S., Tararyshkin S.V., Veber S.L. "Electronic Modulation of the FEL-Oscillator Radiation Power Driven by ERL" Proc. FEL’19. 2019. 39. P. 98-101.
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Exploring the reactivity of b-cyclodextrin-encapsulated anthraquinone-2,6-disulfonate

Published in Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2020

The intracomplex reaction of anthraquinone-2,6-disulfonate in triplet excited state with beta-cyclodextrin and the reaction of 3AQDS:CD complex with external quencher, N-Acetyl-l-Tyrosine, have been studied using laser flash photolysis, 1H NMR and 1H CIDNP

Recommended citation: Babenko S.V., Melnikov A.R., Tsentalovich Y.P., Kruppa A.I. "Exploring the reactivity of b-cyclodextrin-encapsulated anthraquinone-2,6-disulfonate." J. Incl. Phenom. Macro. 2020. 97(1). P. 121-127.
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The Radiation Beamline of Novosibirsk Free-Electron Laser Facility Operating in Terahertz, Far-Infrared, and Mid-Infrared Ranges

Published in IEEE Transactions on Terahertz Science and Technology, 2020

In this work, we describe the 120-m beamline for transporting the radiation of the Novosibirsk FEL facility, consisting of three FELs of the terahertz (THz), far-infrared, and mid-infrared ranges

Recommended citation: Kubarev V.V., Sozinov G.I., Scheglov M.A., Vodopyanov A.V., Sidorov A.V., Melnikov A.R., Veber S.L. "The Radiation Beamline of Novosibirsk Free-Electron Laser Facility Operating in Terahertz, Far-Infrared, and Mid-Infrared Ranges." IEEE Trans. Terahertz Sci. Technol. 2020. 10(6). P. 634-646.
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Technical and software improvements of the EPR spectroscopy endstation at the NovoFEL facility: Status 2020

Published in AIP Conference Proceedings, 2020

In this work, the current status (2020) of the EPR endstation at the NovoFEL facility is described

Recommended citation: Melnikov A.R., Kiskin M.A., Getmanov Y.V., Shevchenko O.A., Fedin M.V., Veber S.L. "Technical and software improvements of the EPR spectroscopy endstation at the NovoFEL facility: Status 2020." AIP Conf. Proc. 2020. 2299(1). Art. Num. 030010.
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Broadband multimodal THz waveguides for efficient transfer of high-power radiation in space-confined conditions

Published in Optics & Laser Technology, 2021

In this work, we present the design and fabrication of multimodal hollow THz waveguides used at the X-band Electron Paramagnetic Resonance endstation of the Novosibirsk Free Electron Laser facility

Recommended citation: Melnikov A.R., Samsonenko A.A., Getmanov Y.V., Shevchenko O.A., Shevchenko D.A., Stepanov A.A., Fedin M.V., Yurkin M.A., Veber S.L. "Broadband multimodal THz waveguides for efficient transfer of high-power radiation in space-confined conditions." Opt. Laser Technol. 2021. 143. Art. Num. 107375.
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Application of Pyroelectric Sensors Based on PVDF Films for EPR Spectra Detection by Heat Release

Published in Sensors, 2021

This paper presents the use pyroelectric film sensors for detecting EPR signals

Recommended citation: Melnikov A.R., Zikirin S.B., Kalneus E.V., Ivannikov V.I., Grishin Y.A., Anisimov O.A. "Application of Pyroelectric Sensors Based on PVDF Films for EPR Spectra Detection by Heat Release." Sensors. 2021. 21(24). Art. Num. 8426.
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Temperature dynamics of magnetoactive compounds under terahertz irradiation: characterization by an EPR study

Published in Russian Chemical Bulletin, 2022

In this paper, we studied effects of powerful terahertz radiation on the spin state of Cu(II) based paramagnetic system

Recommended citation: Tumanov S.V., Melnikov A.R., Artiukhova N.A., Bogomyakov A.S., Shevchenko O.A., Getmanov Y.V., Ovcharenko V.I., Fedin M.V., Veber S.L. "Temperature dynamics of magnetoactive compounds under terahertz irradiation: characterization by an EPR study." Russ. Chem. Bull. 2022. 71(7). P. 1378-1384.
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The role of Heisenberg spin exchange and the quantum Zeno effect in the spin-selective reaction between spin-1/2 and spin-1 particles

Published in The Journal of Chemical Physics, 2022

This theoretical paper describes a kinetic model of the irreversible reaction between the spin-1/2 and spin-1 particles in an encounter complex with the reactive doublet state

Recommended citation: Bagryansky V.A., Melnikov A.R., Molin Y.N., Borovkov V.I. "The role of Heisenberg spin exchange and the quantum Zeno effect in the spin-selective reaction between spin-1/2 and spin-1 particles." J. Chem. Phys. 2023. 157(6). Art. Num. 064306.
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A broadband pulse EPR spectrometer for high-throughput measurements in the X-band

Published in Journal of Magnetic Resonance Open, 2022

This paper describes a homemade X-band pulsed EPR spectrometer

Recommended citation: Isaev N.P., Melnikov A.R., Lomanovich K.A., Dugin M.V., Ivanov M.Y., Polovyanenko D.N., Veber S.L., Bowman M.K., Bagryanskaya E.G. "A broadband pulse EPR spectrometer for high-throughput measurements in the X-band." J. Magn. Res. Open. 2022. 14-15. Art. Num. 100092.
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Sensitivity optimization in pulse EPR experiments with photo-labels by multiple-echo-integrated dynamical decoupling

Published in Physical Chemistry Chemical Physics, 2023

In this paper, we demonstrate that the use of Carr–Parcel–Meiboom–Gill blocks followed by multiple echo integration is a promising route for sensitivity gain in pulsed EPR utilizing photo-excited triplet states

Recommended citation: Sannikova N.E., Melnikov A.R., Veber S.L., Krumkacheva O.A., Fedin M.V. "Sensitivity optimization in pulse EPR experiments with photo-labels by multiple-echo-integrated dynamical decoupling." Phys. Chem. Chem. Phys. 2023. 25(17). P. 11971-11980.
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Magnetic Field Controller

Published in Patent RU2799103C1 (Russian Federation), 2023

Russian patent RU2799103C1 on a Hall-effect controller for constant magnetic fields

Recommended citation: Bizin M.A., Isaev N.P., Baranov S.A., Melnikov A.R., Veber S.L. "Magnetic Field Controller." Patent RU2799103C1. 2023.
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Comparative Study of Single Crystal and Polymeric Pyroelectric Detectors in the 0.9–2.0 THz Range Using Monochromatic Laser Radiation of the NovoFEL

Published in Polymers, 2023

This work compares the performance of six different detectors, based on either LaTiO3 crystal or different polymeric films, using monochromatic radiation of the Novosibirsk Free Electron Laser facility (NovoFEL) in the frequency range of 0.9–2.0 THz

Recommended citation: Melnikov A.R., Kalneus E.V., Getmanov Y.V., Shevchenko D.A., Gerasimov V.V., Anisimov O.A., Fedin M.V., Veber S.L. "Comparative Study of Single Crystal and Polymeric Pyroelectric Detectors in the 0.9–2.0 THz Range Using Monochromatic Laser Radiation of the NovoFEL." Polymers. 2023. 15(20). Art. Num. 4124.
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Photophysics and Photochemistry of Nickel(II) Diselenophosphinate in CCl₄

Published in High Energy Chemistry, 2023

The nature of the photoprocess of Nickel(II) Diselenophosphinate in CCl₄ were determined y the EPR, steady-state and time-resolved optical spectroscopy methods

Recommended citation: Mikheylis A.V., Grivin V.P., Pozdnyakov I.P., Melnikov A.A., Melnikov A.R., Sadykov E.Kh., Artem’ev A.V. "Photophysics and Photochemistry of Nickel(II) Diselenophosphinate in CCl₄." High Energy Chem. 2023. 57(3). P. S433-S440.
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Inductive detection of temperature-induced magnetization dynamics of molecular spin systems

Published in The Journal of Chemical Physics, 2024

In this paper, we proposed an inductive detection of temperature-induced magnetization dynamics as applied to the study of molecular spin systems and describe the general design and construction of an induction probehead

Recommended citation: Melnikov A.R., Ivanov M.Y., Samsonenko A.A., Getmanov Y.V., Nikovskiy I.A., Matiukhina A.K., Zorina-Tikhonova E.N., Voronina J.K., Goloveshkin A.S., Babeshkin K.A., Efimov N.N., Kiskin M.A., Eremenko I.L., Fedin M.V., Veber S.L. "Inductive detection of temperature-induced magnetization dynamics of molecular spin systems ." J. Chem. Phys. 2024. 160(22). Art. Num. 224201.
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Calculation of π Using a Molecular Electron Spin Qubit Implemented by Pulsed Electron Paramagnetic Resonance

Published in The Journal of Physical Chemistry Letters, 2024

This paper describes an interesting method to compare the performance of different mocelular electron spin qubits

Recommended citation: Borodulina A.V., Melnikov A.R., Bochkin G.A., Fedin M.V., Fel’dman, E.B., Veber S.L. "Calculation of π Using a Molecular Electron Spin Qubit Implemented by Pulsed Electron Paramagnetic Resonance." J. Phys. Chem. Lett. 2024. 15(31). P. 8026-8031.
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Scalable Approach for Grafting Qubit Candidates onto the Surface of MOF-808 Framework

Published in Russian Journal of Coordination Chemistry, 2024

In this work a simple and scalable approach to obtain qubit candidates based on stable organic radical 3-carboxy-proxyl and MOF-808 framework was demonstrated

Recommended citation: Tomilov A.S., Yazikova A.A., Melnikov A.R., Smirnova K.A., Poryvaev A.S., Fedin M.V. "Scalable Approach for Grafting Qubit Candidates onto the Surface of MOF-808 Framework." Russ. J. Coord. Chem. 2024. 50(9). P. 646-652.
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Temperature Dependence of the Sensitivity of PVDF Pyroelectric Sensors to THz Radiation: Towards Cryogenic Applications

Published in Sensors, 2024

We characterized the performance of the PVDF sensor at helium temperatures.

Recommended citation: Sinelnikov A.N., Melnikov A.R., Getmanov Y.V., Kolomeec D.A., Kalneus E.V., Fedin M.V., Veber S.L. "Temperature Dependence of the Sensitivity of PVDF Pyroelectric Sensors to THz Radiation: Towards Cryogenic Applications." Sensors. 2024. 24. Art. Num. 5808.
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Paramagnetic Gas Adsorbed in Metal–Organic Framework: A Promising Platform for Spin Qubits Design

Published in The Journal of Physical Chemistry C, 2025

This paper is about nitric oxide (NO) in MOF-808 matrix

Recommended citation: Yazikova A.A., Tomilov A.S., Afimchenko N.A., Zilberberg I.L., Melnikov A.R., Smirnova K.A., Poryvaev A.S., Fedin M.V. "Paramagnetic Gas Adsorbed in Metal–Organic Framework: A Promising Platform for Spin Qubits Design." J. Phys. Chem. C. 2025. 129(17). P. 8455-8463.
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Inter-Kramers electric quadrupole transitions in high-spin systems induced by resonant alternating inhomogeneous electric field

Published in The Journal of Applied Physics, 2025

This theoretical paper compares E2 and M1 transitions in single-molecule magnets

Recommended citation: Maryasov A.G., Melnikov A.R., Fedin M.V., Veber S.L. "Inter-Kramers electric quadrupole transitions in high-spin systems induced by resonant alternating inhomogeneous electric field." J. Appl. Phys. 2025. 138(12). Art. Num. 123906.
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Monitoring S=0 ↔ S=2 Spin-State Switching in Fe(II) Complex Using FT EPR and Trityl Radical as Local Magnetic Field Sensor

Published in Applied Magnetic Resonance, 2025

In this paper, we proposed a contactless spin probe to monitor spin crossover transitions in EPR-silent coordination compounds

Recommended citation: Borodulina A.V., Melnikov A.R., Samsonenko A.A., Rogozhnikova O.Yu., Tormyshev V.M., Fedin M.V., Veber S.L. "Monitoring S=0 ↔ S=2 Spin-State Switching in Fe(II) Complex Using FT EPR and Trityl Radical as Local Magnetic Field Sensor" Appl. Magn. Res. 2025. 56. P. 1535–1547.
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Thermomagnetic Bistability, Colossal Negative Thermal Expansion, and THz-Heat-Induced Switching in Cu-Nitroxide Complex

Published in Angewandte Chemie International Edition, 2025

In this paper, we report the first Cu(II)-nitroxide complex that exhibits TIESST-driven bistability up to 116 K

Recommended citation: Smirnova K., Golomolzina I., Fokin S., Tolstikov S., Chernavin P., Letyagin G., Romanenko G., Zaitsev K., Melnikov A., Veber S., Fedin M., Bogomyakov A. "Thermomagnetic Bistability, Colossal Negative Thermal Expansion, and THz-Heat-Induced Switching in Cu-Nitroxide Complex" Angew. Chem. Int. Ed. 2025. Art. Num. e202514043.
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Application of pulsed heating in time-resolved EPR spectroscopy for longitudinal relaxation measurements

Published in The Journal of Chemical Physics, 2025

In this paper, we propose a new variant of transient (TR) EPR spectroscopy for measuring spin-lattice relaxation time in magnetically concentrated compounds

Recommended citation: Melnikov A.R., Maryasov A.G., Ishchenko A.S., Getmanov Y.V., Isaev N.P., Efimov N.N., Fedin M.V., Veber S.L. "Application of pulsed heating in time-resolved EPR spectroscopy for longitudinal relaxation measurements" J. Chem. Phys. 2025. 163(16). Art. Num. 164201.
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Atomize: A Modular Software for Control and Automation of Scientific and Industrial Instruments

Published in Journal of Open Research Software, 2025

In this paper, an open sources software for control and automation of scientific and industrial instruments is described

Recommended citation: Melnikov A., Vedkal A., Ishchenko A., Veber S. "Atomize: A Modular Software for Control and Automation of Scientific and Industrial Instruments" J. Open Res. Softw. 2025. 13(1). Art. Num. 26.
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Chemically Tunable Spin Frustrated Triangles as New Candidates for Molecular Spin Qubits

Published in ChemRxiv, 2026

An isostructural series of Cu(II), Co(II) and Mn(II) spin triangles on a triaminoguanidine scaffold, with microsecond phase memory times, as a chemically controlled platform for spin electric coupling

Recommended citation: Shukla S., Ghosh S., Hossain S.M., Sarkar A., Shanmugam M., Mehta S., Ishchenko A.S., Melnikov A.R., Lunghi A., Veber S.L., McInnes E.J.L., Collison D., Sarma D.D., Mondal A. "Chemically Tunable Spin Frustrated Triangles as New Candidates for Molecular Spin Qubits" ChemRxiv 2026. Preprint.
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Determination of zero-field splitting in magnetically diluted cobalt(II)-based single molecule magnets using circular dichroism Fourier-transform IR spectroscopy

Published in The Journal of Chemical Physics, 2026

In this paper, we propose a method for the rapid determination of the zero-field splitting in cobalt(II)-based single-molecule magnets based on circular dichroism in a standard FTIR spectrometer, without a superconducting magnet

Recommended citation: Borodulina A.V., Melnikov A.R., Fedin M.V., Veber S.L. "Determination of zero-field splitting in magnetically diluted cobalt(II)-based single molecule magnets using circular dichroism Fourier-transform IR spectroscopy" J. Chem. Phys. 2026. 164(22). Art. Num. 224203.
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Highly Efficient 3-in-1 FPGA-Based Unit Combining an ADC, DAC, and Multichannel Pulse Generator for Pulsed EPR Spectroscopy

Published in arXiv, 2026

A single PCIe card combining a 10 GS/s DAC, a 2.5 GS/s ADC and an 11-channel pulse generator, integrated into Atomize, that reaches close to 100% time efficiency in pulsed EPR experiments

Recommended citation: Isaev N.P., Melnikov A.R., Vedkal A.V., Ishchenko A.S., Sokolov A.M., Voronkov E.A., Veber S.L. "Highly Efficient 3-in-1 FPGA-Based Unit Combining an ADC, DAC, and Multichannel Pulse Generator for Pulsed EPR Spectroscopy" arXiv 2026. Preprint. arXiv:2608.16151.
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Highly efficient exciplex formation in X-irradiated alkane solutions for luminophores with short fluorescence lifetimes

Published: July 13, 2014

X-ray generation of electronically excited molecules via the step of radical ion pair recombination offers unique advantages of the possibility of working in the conditions of optically dense sample (typical concentrations of positive charge acceptor are about 10⁻² M or higher) while having an almost homogeneous formation of the excited molecules over the sample, as X-radiation is weakly absorbed by an organic sample. Furthermore, in case of X-ray generation another molecule, corresponding to the second partner of the pair, is always found next to the excited molecule formed upon recombination. This can be either a molecule of the same compound, or a molecule of a different component deliberately introduced into the solution. As a result, not only the expected emission of the excited molecule becomes possible, but also the formation of excited complexes, such as exciplexes. Thus X-ray generation opens the way to exciplexes for systems with a very short fluorescence lifetime of the luminophore molecule, as recombination creates optimal conditions for the high efficiency exciplex formation.

Magnetosensitive exciplex emission in X-irradiated alkane solutions

Published: March 15, 2015

The emission of optically generated exciplex is well-known to be magnetosensitive. Magnetic field effects (MFE) are based on the reversibility of transitions between the radical ion pair state and the exciplex in the solvent of corresponding viscosity and polarity.

X-ray generated exciplexes of diphenylacetylenes with CF3 or OMe substituent group

Published: June 25, 2017

This work reports the investigation of six synthesized diphenylacetylenes (DPAs) with systematically varied position of donor (-OMe) or acceptor (-CF₃) substituent group and unsubstituted DPA. DPAs under study are found to have different luminescence properties, namely, luminescence lifetimes vary from less than 200 ps to 0.96 ns, and quantum yields vary from 0.005 to 0.45. Nevertheless, all of substituted DPAs efficiently form exciplexes with N,N-dimethylaniline under X-ray irradiation of n-dodecane solution via radical ion pair recombination. The exciplex lifetime and the position of exciplex emission band depend strongly on the nature of the substituent group. For instance, the acceptor groups shift exciplex emission bathochromically, compared to unsubstituted DPA, whereas the donor groups shift it hypsochromically. The shifting of the exciplex emission is found to correlate with electron affinity of corresponded substituted DPA. Electron affinities are obtained by means of quantum chemical calculations at CAM-B3LYP level of theory and 6-31+G(d,p) basis set.

Technical aspects and possible applications of the THz radiation electronic modulation system of NovoFEL

Published: September 17, 2019

The Novosibirsk Free Electron Laser (NovoFEL) facility is able to produce high-power tunable laser radiation in quasi-continuous mode in the terahertz (THz) frequency range. The ability to save the peak power of this radiation together with the possibility to control radiation time is of great importance in a number of experiments. In this work we propose the approach suitable for radiation modulation of free electron lasers based on recuperation design, which is based on periodic phase shift of electron bunches with respect to radiation stored in optical cavity. THz macropulses in the range of several microseconds (limited by quality factor of the optical resonator and FEL gain) to several hundred microseconds can be generated by this approach in three different frequency ranges of NovoFEL, i.e. mid-IR (~1100 cm⁻¹), far-IR (~200 cm⁻¹), and THz (~40 cm⁻¹). The macropulse repetition rate is controlled by an external trigger. For each of three available frequency ranges the typical rise and decay of the macropulse were measured and interpreted. The possible applications of short THz macropulses with the maximum available peak power were shown by time-resolved electron paramagnetic resonance (EPR) spectroscopy.

Electronic system for modulating THz radiation at Novosibirsk free electron laser: possible applications and technical aspects

Published: September 24, 2019

Electronic system for modulating THz radiation of the Novosibirsk free electron laser: technical aspects and possible applications

Published: September 01, 2020

The Novosibirsk free electron laser (FEL) is able to generate high-power tunable laser radiation in quasi-continuous mode in the terahertz (THz) frequency range. The ability to preserve the peak power of this radiation together with the possibility to control the radiation time is of great importance in a number of experiments. In this work an approach was developed and implemented that allows THz macropulses to be created at the Novosibirsk FEL with any repetition rate and almost any duration. The proposed electronic modulation system is based on a periodic shift of the phase of electron bunch injection. Such a shift suppresses lasing and forms macropulses. The system is embedded into the existing electronic infrastructure of the Novosibirsk FEL and can be triggered directly at the user endstations.

Atomize: open source modular software for working with scientific devices and combining them into a spectrometer

Published: September 05, 2022

Remote control of spectrometers is usually carried out using home-written programs, which are often restricted to doing a certain experiment with a specific set of devices. In contrast, the programs like fsc2 and Atomize are much more flexible, since they are based on a modular approach for communication with device and scripting language for data measuring. For each available device, there is a special module that allows controlling it using high-level functions with self-explanatory name like oscilloscope.get_curve(). This makes it easy to set up a new experiment or modify an existing one, without requiring detailed knowledge about the internals of the program or exactly how the devices are controlled by the computer.

Temperature jump spectroscopy under pulsed THz radiation: a way to measure T1 of magnetically concentrated substances

Published: September 05, 2022

Spin-lattice and spin-spin interactions play an important role in a number of physical phenomena with applied potential, i.e. magnetic relaxation in single-molecule magnets (SMMs), entanglement of a quantum system with its environment, decoherence of magnetic qubits. In particular, for the technological application of SMMs, the low rate of spin-lattice relaxation (T₁) is one of the critical factors that requires a fundamental understanding. To determine T₁ of SMM, the magnetic susceptibility of a macroscopic sample is usually measured by alternating current SQUID magnetometry. Another direct method is pulsed EPR spectroscopy, which requires diamagnetically diluted samples to suppress spin-spin interactions.

High stability and low noise X-band FT EPR spectrometer with AWG unit and flexible open-source software for applications in pulse dipolar and hyperfine spectroscopy

Published: July 10, 2023

Fourier transform (FT) experimental techniques have long been the standard for nuclear magnetic resonance. The situation is quite different in electron paramagnetic resonance (EPR), where progress is limited by the necessary advance in instrumentation. The frontiers of modern EPR spectroscopy are defined by home-built spectrometers that combine high microwave (MW) power with broadband excitation capability.

T-jump spectroscopy under pulsed THz radiation: a universal way to measure T1 of magnetically concentrated single-molecule magnets

Published: September 10, 2023

Spin-lattice and spin-spin interactions play a crucial role in various phenomena with an applied potential. In particular, any technological application of single-molecule magnets (SMMs) requires a low rate of spin-lattice relaxation (T₁). To determine T₁ of SMM, the magnetic susceptibility of a macroscopic powder sample is usually measured at different temperatures by alternating current SQUID magnetometry. Another direct method is pulsed electron paramagnetic resonance (EPR) spectroscopy that can be used only for diamagnetically diluted samples to suppress spin-spin interactions.

Study of single-crystal and polymer pyroelectric detectors in the 0.9–2.0 THz range using the Novosibirsk FEL

Published: June 25, 2024

The development of efficient and reliable detectors operating at room temperature is essential for the advance of science and technology that rely on terahertz (THz) radiation. Pyroelectric THz detectors are among the best candidates, given their variety, excellent technical characteristics, ease of fabrication and reliability. In this work we compare six different detectors based either on a LaTiO₃ crystal or on various polymer films, using monochromatic radiation of the Novosibirsk free electron laser in the 0.9–2.0 THz frequency range. Their main characteristics were determined for all detectors, including the noise equivalent power and the frequency dependence of the response. Possible reasons for the differences between the characteristics obtained are discussed on the basis of the physicochemical and optical properties of the sensitive area. Three detectors showed sufficient sensitivity to record the shape and duration of THz macropulses using only a small fraction of the THz radiation from the main beam. This makes it possible to characterise the parameters of THz radiation accurately in parallel with the main experiment at various specialised user endstations at synchrotrons and free electron lasers. As an example of such characterisation, the stability of the average power of the Novosibirsk FEL was studied at the electron paramagnetic resonance (EPR) spectroscopy endstation.

EPR spectroscopy endstation at the Novosibirsk free electron laser facility: Status 2024

Published: October 22, 2024

EPR spectroscopy endstation at the Novosibirsk free electron laser facility: Status 2025

Published: October 13, 2025

The electron paramagnetic resonance (EPR) endstation at the Novosibirsk free electron laser facility allows performing continuous wave and time-resolved EPR experiments under pulsed irradiation of the system under study by terahertz (THz, 25-111 cm⁻¹, 90-400 μm; 0.75-3.3 THz) radiation. Recently, several improvements of experimental equipment and software have been carried out at the endstation to realize the pulsed EPR spectroscopy, including the use of THz radiation pulses. Herein, we present the current status of the EPR spectroscopy endstation. First, an X-band pulsed EPR spectrometer is described, which was developed for spin relaxation measurements and for applications in pulsed dipolar and hyperfine spectroscopy. The Atomize modular open source software is used to control the spectrometer. The software allows the operator to observe the processed signal (after Fourier transform, phase cycling, etc.) in real time, both for setting up the experiment (selection of magnetic field, setting of pulse intervals, etc.) and for monitoring the progress of the experiment. Second, two specialized probeheads are presented, which were created to perform different types of experiments under THz radiation in Faraday geometry. The first is a microwave probehead for pulsed EPR experiments, while the second allows an inductive detection of temperature-induced magnetization dynamics. To evaluate the performance, several coordination compounds were investigated using low-energy pulses of a terahertz free electron laser of the Novosibirsk free electron laser facility. These experimental capabilities were applied to investigate THz-assisted processes in a family of field-induced Co(II)-based single-ion magnets (SIMs) with S = 3/2, whose structural and magnetic properties had been thoroughly characterized in prior studies. By varying the wavelength of THz radiation, three cases were studied in detail: (i) off-resonance irradiation, (ii) THz-pumping of m_S = −3/2 ↔ m_S = −1/2 transitions, and (iii) THz-pumping of m_S = +3/2 ↔ m_S = +1/2 transitions. Experiments (i) revealed temperature-induced magnetization dynamics caused by lattice heating under THz irradiation. Experiments (ii) and (iii) clearly demonstrated direct excitation of spin transitions by THz radiation, resulting in a non-equilibrium population of the ground state. By tuning the THz wavelength, the SIM magnetization could be polarized in both directions: toward “heating” or “cooling”. In absolute values, at a base temperature of 3.4 K, THz excitation induced a 0.4 K temperature shift in the spin system. This work was supported by the Russian Science Foundation 23-73-00042.

Polarization of the ground Kramers doublet in single-molecule magnets based on Co(II) by pumping the spin system with resonant pulsed THz radiation

Published: June 22, 2026

Single-molecule magnets (SMMs) exhibit unique magnetic properties but face challenges in practical use due to difficulties in controlling their magnetization. In this work, pulsed, frequency-tunable THz radiation from the Novosibirsk Free Electron Laser (NovoFEL) was combined with electron paramagnetic resonance (EPR) techniques to study THz-induced processes in Co(II)-based SMMs. By tuning the wavelength, direct excitation of magnetic dipole transitions was achieved, leading to non-equilibrium populations of the ground spin state.

Optical control of magnetization in Co(II)-based single-molecule magnets via resonant pulsed THz excitation

Published: October 18, 2026

Single-molecule magnets (SMMs) are a class of magnetic materials that combine a number of unique characteristics compared to conventional magnets, such as low density, low electrical conductivity, and optical transparency. A key obstacle to their practical application is the absence of an effective and reliable route to control their magnetization. Such control can be achieved by directly exciting the ground spin state with photons. This strategy was demonstrated in the early 2000s for the well-known Fe₈ single-molecule magnet, using a microwave generator (~110 GHz) as a source of resonant photons. Since then, considerable progress in the chemical tuning of SMMs has substantially increased the energy gap between the ground and first excited states, which now extends into the terahertz (THz) and far-infrared ranges. This has hindered the study of direct excitation of the SMM spin system, owing to the scarcity of suitable radiation sources operating in these ranges.

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