Observation of magnetic transition in quantum nanomagnet Mn4Br

2019-12-06 05:36:16

phase magnetic transition Japan Mn4Br

责任者: Yamaguchi, A.;Kusumi, N.;Ishimoto, H.;Mitamura, H.;Goto, T.;Mori, N.;Nakano, M.;Awaga, K.;Yo, J.;Hendrickson, D.N.;Christou, G. 单位: Inst. for Solid State Phys., Univ. of Tokyo, Kashiwa, Japan 来源出处: Journal of the Physical Society of Japan(J. Phys. Soc. Jpn. (Japan)),2002/02/,71(2):414-17 摘要: The magnetization of the polycrystalline manganese cluster Mn4Br was measured down to 0.13 K under a magnetic field of 15 kOe. It shows a gradual drop at around 1.5 K and the heat capacity measurement at 0 kOe reveals a sharp anomaly at 1.33 K, indicating the occurrence of a second-order antiferromagnetic (AFM) phase transition. The M-H curve well below the transition temperature TN shows a step around 2.5 kOe, which probably corresponds to the transition from the AFM phase to metamagnetic (MM) phase. The observed field agrees with that estimated from TN for the MM transition, using a simple molecular field theory. This is the first observation of a well-defined AFM and also a MM phase among the many manganese clusters with a high-spin ground state that function as molecular nanomagnets 关键词: antiferromagnetic materials;magnetic transitions;magnetisation;manganese compounds;nanostructured materials;specific heat;magnetic transition;quantum nanomagnet Mn4Br;magnetization;heat capacity;second-order antiferromagnetic phase transition;metamagnetic phase;high-spin ground state;0.13 K;1.5 K;1.33 K;Mn4Br