Quantum versus classical nature of the low-temperature magnetic phase transition in TbAl.sub.3./sub.(BO.sub.3./sub.).sub.4./sub.

0563775 - FZÚ 2023 RIV US eng J - Článek v odborném periodiku
Zajarniuk, T. - Szewczyk, A. - Gutowska, M.U. - Puźniak, R. - Szymczak, H. - Gudim, I. - Bedarev, V. A. - Pashchenko, Mariia - Tomczak, P. - Szuszkiewicz, W.
Quantum versus classical nature of the low-temperature magnetic phase transition in TbAl₃(BO₃)₄.
Physical Review B. Roč. 105, č. 9 (2022), č. článku 094418. ISSN 2469-9950. E-ISSN 2469-9969
Institucionální podpora: RVO:68378271
Klíčová slova: specific heat * magnetization * quantum fluctuations * ferromagnetic ordering
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 3.7, rok: 2022
Způsob publikování: Omezený přístup
https://doi.org/10.1103/PhysRevB.105.094418

Specific heat C-B of a TbAl3(BO3)(4) crystal was studied for 50 mK < T < 300 K with emphasis on T < 1 K where a phase transition was found at T-c = 0.68 K. Nuclear, nonphonon (C-m), and lattice contributions to C-B were separated. Lowering of T-c with an increase in magnetic field parallel to the easy magnetization axis (B-parallel to) was found. It was established that C-m and a Gruneisen ratio depend on B-parallel to and T in a way characteristic of systems in which a classical transition is driven by quantum fluctuations (QFs) to a quantum critical point at T = 0 by tuning a control parameter (B-parallel to). The B-parallel to T phase diagram was constructed, and the dynamical critical exponent 0.82 <= z <= 0.96 was assessed. Nature of the transition was not established explicitly. Magnetization studies point at the ferromagnetic ordering of Tb3+ magnetic moments, however, lowering of T-c with increase in B-parallel to is opposite to the classical behavior. Hence, a dominant role of QFs was supposed.
Trvalý link: https://hdl.handle.net/11104/0335583