Magnetic field effects on the diffuse scattering of a spin-frustrated spinel ferrite ZnFe2O4 single crystal

Magnetic diffuse scattering of ZnFe2O4 originated from the spin-frustration on the network of the corner sharing tetrahedra has been studied under magnetic fields up to 7T by neutron scattering. The previous work indicated that the characteristic diffuse scattering distributed in the (HKO) zone of this compound can be well explained with the assumptions that the nearest-neighbor interaction is ferromagnetic and the third-neighbor interaction is antiferromagnetic. In the present experiments it is found that the fields up to 7T dramatically decrease the spherical diffuse scattering around the (400) Bragg point. The features of the field dependence of the diffuse scattering around this (400) point and that along the zone boundary passing through the (300) point are shown. Strangely enough, the ferromagnetic correlations in ZnFe2O4 are weakened rather than strengthened in the magnetic field. (C) 2003 Elsevier B.V. All rights reserved.