[PDF]     https://doi.org/10.3952/physics.2026.66.2.5

Open access article / Atviros prieigos straipsnis
Lith. J. Phys. 66, 107–112 (2026)
 

EPR OF X-RAY-IRRADIATED [(CH3)2NH2][Zn(HCOO)3] HYBRID PEROVSKITE
  Gediminas Usevičiusa, Ignas Pociusa, Rokas Dobužinskasb, Mirosław Mączkac, Gytis Sliaužysb, Jūras Banysa, and Mantas Šimėnasa
aInstitute of Applied Electrodynamics and Telecommunications, Faculty of Physics, Vilnius University, Saulėtekio 3, 10257 Vilnius, Lithuania
bInstitute of Chemical Physics, Faculty of Physics, Vilnius University, Saulėtekio 3, 10257 Vilnius, Lithuania
cInstitute of Low Temperature and Structure Research, Polish Academy of Sciences, PL-50-422 Wroclaw, Poland
Email: gediminas.usevicius@ff.vu.lt

Received 7 January 2026; accepted 21 January 2026

Incorporating paramagnetic metal ions into hybrid materials is a standard practice to enable electron paramagnetic resonance (EPR) studies of phase transitions and dynamics. Yet, the inclusion of foreign ions in the lattice can significantly distort the local structure, resulting in the inaccurate understanding of the material properties. Less invasive paramagnetic defects can be formed by high energy irradiation. Here, we report a continuous-wave (CW) EPR study of X-ray-irradiated [(CH3)2NH2][Zn(HCOO)3] hybrid perovskite, which possesses a structural phase transition at ~160 K. The CW EPR spectrum reveals a rhombic g-tensor with no clearly resolved hyperfine splittings. Assisted by the DFT calculations, we assign the spectrum to a radical species on the formate linker. The temperature dependence of the measured gzz component reveals a broad anomaly in a broad temperature range close to the phase transition point, which we relate to the change in the dynamics of a formate linker.
Keywords: EPR, hybrid perovskite, phase transition


RENTGENO SPINDULIAIS APŠVITINTO [(CH3)2NH2][Zn(HCOO)3] HIBRIDINIO PEROVSKITO EPR TYRIMAS
Gediminas Usevičiusa, Ignas Pociusa, Rokas Dobužinskasb, Mirosław Mączkac, Gytis Sliaužysb, Jūras Banysa, Mantas Šimėnasa
aVilniaus universiteto Fizikos fakulteto Taikomosios elektrodinamikos ir telekomunikacijų institutas, Vilnius, Lietuva
bVilniaus universiteto Fizikos fakulteto Cheminės fizikos institutas, Vilnius, Lietuva
cLenkijos mokslų akademijos Žemų temperatūrų ir struktūros tyrimų institutas, Vroclavas, Lenkija
 
Paramagnetinių metalo jonų įterpimas į hibridines medžiagas yra įprasta praktika, leidžianti taikyti elektronų paramagnetinio rezonanso (EPR) metodus fazinių virsmų ir dinamikos tyrimams. Tačiau svetimų jonų įtraukimas į gardelę gali reikšmingai iškraipyti lokalią struktūrą, todėl medžiagos savybės gali būti interpretuojamos netiksliai. Mažiau invaziniai paramagnetiniai defektai gali būti suformuoti apšvitinant bandinį didelės energijos spinduliuote. Šiame darbe pateikiamas rentgeno spinduliais apšvitinto [(CH3)2NH2][Zn(HCOO)3] hibridinio perovskito tolydžiosios bangos režimo (CW) EPR tyrimas; ši medžiaga pasižymi struktūriniu faziniu perėjimu ties ~160 K. CW EPR spektras atskleidžia rombinį g tenzorių be išskirtų hipersmulkiosios sąveikos signalų. Pasitelkę tankio funkcionalo teorijos (DFT) skaičiavimus, spektrą priskiriame radikalui, lokalizuotam formiato jungtyje. Išmatuotos gzz komponentės temperatūrinė priklausomybė pasižymi plačia anomalija plačiame temperatūrų intervale netoli fazinio virsmo taško, kurią siejame su formiato jungties dinamikos pokyčiais.


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