Magnetic structure determination of novel monoclinic Kondo lattice YbPt5B2

In course of Yb-Pt-B phase diagram studies, novel YbPt5B2 was detected, which crystallises in a monoclinic crystal structure (space group C2/m) with its own YbPt5B2-type. Bulk property measurements reveal two magnetic phase transitions at T_mag1 ~ 8 K and T_mag2 ~ 4 K. For temperatures below T_mag2, increasing magnetic fields cause two successive field induced phase transitions below 3 T. In order to gain insight into the complicated magnetic structure and the respective temperature and field-dependent phase transitions, microscopic insights by neutron studies are indispensable. Magnetic order (magnitude and arrangements of the Yb magnetic moments) is expected to be a result of a complicated overlay of RKKY interaction, Kondo and crystalline electric field effects. We therefore propose neutron diffraction measurements on YbPt5B2 using the WISH diffractometer.

在Yb-Pt-B三元体系相图的研究过程中，我们发现了新型化合物YbPt5B2。该化合物具有专属的YbPt5B2型晶体结构，结晶于单斜晶系，空间群为C2/m。宏观物性测试结果显示，该化合物存在两处磁相变点：T_mag1约为8 K，T_mag2约为4 K。当温度低于T_mag2时，施加递增的外磁场会在3 T以下引发两次连续的磁场诱导相变。为深入解析其复杂的磁结构以及温度、磁场依赖的相变行为，中子散射实验所提供的微观观测手段不可或缺。该化合物的磁有序行为（即镱离子磁矩的大小与排布方式）被认为是RKKY相互作用、近藤效应与晶场效应三者复杂叠加的结果。因此，我们提议使用WISH衍射仪对YbPt5B2开展中子衍射实验。