Посилання:Thermal expansion of organic superconductor κ-(D₄-BEDT-TTF)₂Cu[N(CN)₂]Br. Isotopic effect / A.V. Dolbin, M.V. Khlistuck, V.B. Eselson, V.G. Gavrilko, N.A. Vinnikov, R.M. Basnukaeva, V.A. Konstantinov, Y. Nakazawa // Физика низких температур. — 2018. — Т. 44, № 12. — С. 1740-1744. — Бібліогр.: 16 назв. — англ.
Підтримка:The authors thank Prof. A. Kawamoto at Hokkaido
University and Prof. H. Taniguchi at Saitama University
for their synthesis of partially deuterated molecules. The
authors are grateful Prof. A. Prokhvatilov for fruitful discussion of result.
Linear thermal expansion coefficient (LTEC) of single crystal κ-(D₄-BEDT-TTF)₂Cu[N(CN)₂]Br was studied across the crystal layers in the temperature range 2–290 K using the method of precise capacitive dilatometry. Below Tc = 11.6 K the LTEC of the sample had a small negative value, which is apparently due to the transition from the paramagnetic metal in the superconducting state. There was a bend of temperature dependence of the LTEC, which shows broad peak around 40 K and can be attributed to the elastic lattice anomaly around the end-point of Mott boundary. A sharp jump in the LTEC values and hysteresis was observed in the area of Tg ~ 75–77 K, what is likely explained by the transition in a glass-like state. The isotope effect in the thermal expansion is discusses, which manifested itself in a shift of the phase transitions in comparison with fully deuterated BEDT-TTF sample.