Antiferromagnetism and Frustration in Ba₂CuWO₆

抄録

Measurements of magnetic susceptibility and magnetic neutron diffraction on powder of ordered complex perovskite Ba₂CuWO₆ have been performed. This compound was expected to be the two-dimensional antiferromagnet with frustrating nearest and next-nearest-neighbor antiferromagnetic interactions. It has been shown that the susceptibility is well fitted by the high-temperature series expansion calculations for the nearest-neighbor square lattice antiferromagnet with S=1/2 and J=-55.5±0.2 K. On the other hand, neither the antiferromagnetic Bragg peak nor clear magnetic diffuse scattering expected for the two-dimensional antiferromagnetic spin correlation has been detected at 15 K. Effects of the frustration in the case of the finite nearest-neighbor interaction are discussed.