Neutron Diffraction Study of Helimagnetic Spinel ZnCr2Se4

Abstract

Neutron diffraction experiments under magnetic fields up to 15 kOe are performed on the helimagnetic spinel ZnCr2Se4. For fields of about 3 to 4 kOe, switching of 90° antiferromagnetic domains occurs. In the same field range, there is also a tilting of the spins rotation axis towards the field direction. In the field range 10 to 15 kOe, canting of the spins towards the field direction occurs as shown experimentally. Hysteresis effects of the boundaries motions are studied. Exchange coefficients are determined, together with estimates of the potential energy associated with the Bloch walls and of the magnetic anisotropy energy.