Anomalous magnetic behavior of Ba2CoO4 with isolated CoO4 tetrahedra

Article

关键词: SPIN-EXCHANGE INTERACTIONS;    DIMER ANALYSIS;    SUPERCONDUCTIVITY;    TRANSITION;    MATTER;    LA;   

DOI  :  10.1103/PhysRevB.99.094416

来源: SCIE

【 摘 要 】

The dimensionality of the electronic and magnetic structure of a given material is generally predetermined by its crystal structure. Here, using elastic and inelastic neutron scattering combined with magnetization measurements, we find unusual magnetic behavior in three-dimensional (3D) Ba2CoO4. In spite of isolated CoO4 tetrahedra, the system exhibits a 3D noncollinear antiferromagnetic order in the ground state with an anomalously large Curie-Weiss temperature of 110 K compared to T-N = 26 K. More unexpectedly, spin dynamics displays quasi-two-dimensional spin-wave dispersion with an unusually large spin gap, and one-dimensional magnetoelastic coupling. Our results indicate that Ba2CoO4 is a unique system for exploring the interplay between isolated polyhedra, low-dimensional magnetism, and spin states in oxides.

【 授权许可】

Free