Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland.
J Phys Condens Matter. 2023 Mar 31;35(24). doi: 10.1088/1361-648X/acc62a.
We address the degeneracy of the ground state multiplet on the 5Reion in double perovskite BaMgReOusing a combination of specific heat measurements and density functional calculations. For BaMgReO, two different ground state multiplets have previously been proposed-a quartet (with degeneracy= 4) (Hirai and Hiroi 2019064712) and a doublet (= 2) (Marjerrison201610701). Here we employ two independent methods for the estimation of phonon contribution in heat capacity data to obtain the magnetic entropySmag, which reflects the degeneracy of the ground state multipletthroughSmag=Rln. In both cases, we obtain that in the temperature range covering 2 to 120 K the released entropy is better described bySmag=Rln2. The detailed nature of the ground state multiplet in BaMgReOremains an open question.
我们使用比热测量和密度泛函计算的组合来解决双钙钛矿 BaMgReO 中 5Re 离子基态多重态的简并问题。对于 BaMgReO，之前已经提出了两种不同的基态多重态-四重态（简并度=4）（Hirai 和 Hiroi 2019064712）和二重态（=2）（Marjerrison201610701）。在这里，我们采用两种独立的方法来估计比热数据中的声子贡献，以获得磁熵 Smag，它通过 Smag=Rln 反映基态多重态的简并度。在两种情况下，我们都得到在覆盖 2 到 120 K 的温度范围内，释放的熵由 Smag=Rln2 更好地描述。BaMgReO 中基态多重态的详细性质仍然是一个悬而未决的问题。
