Quantum versus classical nature of a low-temperature magnetic phase transition in TbAl${}_3$(BO${}_3$)${}_4$

T. Zajarniuk, A. Szewczyk, P. Wisniewski +8

Specific heat, $C_B$, of a TbAl${}_3$(BO${}_3$)${}_4$ 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, n…