IMPACT OF PHASE TRANSITIONS ON THE TEMPERATURE EVOLUTION OF THE ABSORPTION SPECTRA AND THE ELECTRON-PHONON INTERACTION IN (N(C2H5)4)2CoCl2Br2 CRYSTALS
Abstract
We investigated the absorption spectra of (N(C2H5)4)2CoCl2Br2 (TEACCB-2) crystals and determined the parameters of their structure. The absorption bands related to the internal electronic transitions in the Co2+ ion were identified. The impact of phase transitions on the temperature evolution of the absorption spectra was studied. It was shown that the low-energy “tail” of the absorption edge in this material, formed with the participation of the “ligand-metal” charge-transfer electron transitions, possessed an exponential shape which was described by the empirical Urbach’s rule in the two high-temperature crystal phases. On the basis of the analysis of the temperature changes of the main characteristics of the obtained spectra we corrected the temperatures and the phase transition type at T1 = 244 K and T2 = 228 K (in the cooling regime). Besides, for the first time an anomaly was detected at the temperature T3 = 200 K in TEACCB-2 bulk crystals, which was previously observed in the absorption spectrum of TEACCB-2 nanocrystals. This anomaly can be attributed to the phase transition.
About the Authors
V. B. Kapustianyk
Ivan Franko National University of Lviv; Scientific-Technical and Educational Center of Low Temperature Studies of Ivan Franko National University of Lviv
Ukraine
50 Dragomanova Str., Lviv, 79000; Lviv, 79000
Ukraine
50 Dragomanova Str., Lviv, 79000; Lviv, 79000
S. I. Semak
Ivan Franko National University of Lviv
Ukraine
50 Dragomanova Str., Lviv, 79000
Ukraine
50 Dragomanova Str., Lviv, 79000
S. B. Bilchenko
Ivan Franko National University of Lviv
Ukraine
50 Dragomanova Str., Lviv, 79000
Ukraine
50 Dragomanova Str., Lviv, 79000
Yu. Eliyashevskyy
Ivan Franko National University of Lviv
Ukraine
50 Dragomanova Str., Lviv, 79000
Ukraine
50 Dragomanova Str., Lviv, 79000
Yu. V. Chorniy
Ivan Franko National University of Lviv
Ukraine
50 Dragomanova Str., Lviv, 79000
Ukraine
50 Dragomanova Str., Lviv, 79000
P. Yu. Demchenko
Ivan Franko National University of Lviv
Ukraine
50 Dragomanova Str., Lviv, 79000
Ukraine
50 Dragomanova Str., Lviv, 79000
References
1. I. D. Williams, P. W. Brown, N. J. Taylor. Acta Cryst., 48 (1992) 263—266
2. Z. Czapla, S. Dacko. Ferroelectrics, 125 (1992) 17—22
3. K. Hasebe, H. Mashiyama, S. Tanisaki. J. Phys. Soc. Jpn., 49 (1986) 92—94
4. Z. Cummins. Phys. Rep., 185 (1990) 211—411
5. O. Caetano, M. Lopez, A. Mahoui, J. Lapasset, J. Moret, T. Assih, P. Saint-Gregoire. Ferroelectrics, 19 (1995) 69—74
6. З. А. Боброва, В. M. Варикаш. Докл. АН БССР, 30 (1986) 510—512
7. N. Izumi. Bull. Fac. Educ. Kanazawa Univ., 38 (1989) 1—5
8. О. Г. Влох, И. И. Половинко, С. А. Свелеба. ФТТ, 31 (1989) 277—280
9. О. Г. Влох, М. О. Ольхова, И. И. Половинко, С. А. Свелеба, Т. М. Сосновский. Укр. физ. журн., 35 (1990) 1330—1332
10. О. Г. Влох, И. И. Половинко, С. А. Свелеба. Укр. физ. журн., 34 (1989) 673—677
11. О. Г. Влох, М. И. Бублык, И. И. Половинко, М. О. Ольхова, С. А, Свелеба, Т. М. Сосновский. Письма в ЖТФ, 16 (1990) 23—26
12. О. G. Vlokh, V. В. Kapustianik, I. I. Polovinko, S. A. Sveleba, Z. A. Bobrova, V. М. Varikash. Ferroelectrics, 125 (1992) 183—189
13. В. Б. Капустянык, Ю. М. Корчак, С. А. Свелеба, В. И. Мокрый. Журн. прикл. спектр., 67, № 1 (2000) 91—95 [V. B. Kapustyanyk, Y. M. Korchak, S. A. Sveleba, V. I. Mokryi. J. Appl. Spectr., 67 (2000) 119—126]
14. V. Rudyk, I. Kityk, V. Kapustianyk, K. Ozga. Ferroelectrics, 330 (2006) 19—24
15. V. Kapustianyk, V. Rudyk, M. Partyka, I. Kityk, S. Tkaczyk. J. Phys.: Conf. Ser., 79 (2007) 1—8
16. V. Kapustianyk, Ya. Shchur, I. Kityk, V. Rudyk, G. Lach, L. Laskowski, S. Tkaczyk, J. Swiatek, V. Davydov. J. Phys.: Condens. Matter, 20 (2008) 365215
17. В. Б. Капустянык, Ю. И. Элияшевский, С. И. Семак, И. В. Китык. Високочастотный пьезо-электрический преобразователь гигагерцового диапазона, патент № 124018 Украина, МПК H04R 17/00, H04R 17/10, G01N 29/12 (2018)
18. V. Kapustianyk, I. Polovinko, Yu. Korchak, S. Sveleba, R. Tchukvinskyi, S. Dacko, Z. Chapla. Ferroelectrics, 202 (1997) 149—156
19. V. Rudyk, I. Kityk, V. Kapustianyk, K. Ozga. Ferroelectrics, 330, N 1 (2006) 19—24
20. A. Altomare, G. Campi, C. Cuocci, L. Eriksson, C. Giacovazzo, A. Moliterni, R. Rizzi, P.-E. Werner. J. Appl. Crystallogr., 42 (2009) 768—775
21. A. Altomare, C. Cuocci, C. Giacovazzo, A. Moliterni, R. Rizzi, N. Corriero, A. Falcicchio. J. Appl. Crystallogr., 46 (2013) 1231—1235
22. Э. Ливер. Электронная спектроскопия неорганических соединений, Москва, Мир (1987)
23. В. Б. Капустянык, П. К. Йонак, В. П. Рудык. Журн. прикл. спектр., 82, № 4 (2015) 557—563 [V. B. Kapustianyk, P. K. Yonak, V. P. Rudyk. J. Appl. Spectr., 82 (2015) 591—597]
24. V. Kapustianyk, S. Semak, M. Panasyuk, M. Rudko, V. Rudyk. Phase Transition, 92, N 4 (2019) 396—405
25. В. Б. Капустяник. Физика кристаллических ферроиков с органическим катионом, Львов, ЛНУ имени Івана Франко (2006) 345—368
26. V. B. Kapustianyk. Phys. Status Solidi (b), 204 (1997) 877—887
27. V. Kapustianyk, S. Semak, P. Demchenko, I. Girnyk, Yu. Eliyashevskyy. Phase Transition, 91, N 7 (2018) 715—723
28. H. Sumi, A. Sumi. J. Phys. Soc. Jpn., 56 (1987) 2211—2220
29. V. Кapustianik, Yu. Korchak, V. Bazhan. Phys. Status Solidi (b), 218 (2000) 583—590
Review
For citations:
Kapustianyk V.B., Semak S.I., Bilchenko S.B., Eliyashevskyy Yu., Chorniy Yu.V., Demchenko P.Yu. IMPACT OF PHASE TRANSITIONS ON THE TEMPERATURE EVOLUTION OF THE ABSORPTION SPECTRA AND THE ELECTRON-PHONON INTERACTION IN (N(C2H5)4)2CoCl2Br2 CRYSTALS. Zhurnal Prikladnoii Spektroskopii. 2019;86(4):531-538. (In Russ.)
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