Weak ferromagnetism in

• DOI: 10.1007/s100510050950
• Publication Date: 2002-08-25T09:25:39Z
• Authors: V. Skumryev; F. Ott; J.M.D. Coey; A. Anane; J.-P. Renard; L. Pinsard-Gaudart; A. Revcolevschi
• Keywords: 0103 physical sciences; 02 engineering and technology; 0210 nano-technology; 01 natural sciences

The magnetic properties of crystals have been studied. The ac susceptibility has been measured at frequencies ranging from 10 Hz to 1 000 Hz. The x = 0.25 crystal shows a typical ferromagnetic behaviour with a dimensionless SI susceptibility of 6 below limited by the demagnetizing field. Both x = 0 and x = 0.06 crystals show very sharp peaks in and at the Neel points, 139 K and 135 K respectively. This is quite unlike the usual behaviour of an antiferromagnet. Magnetization measurements on an untwinned single crystal of show a weak moment of at 4.2 K which is directed along the c axis. The origin of this canted antiferromagnetic structure is discussed in terms of anisotropy and of Dzyaloshinskii-Moriya interaction. It is concluded that anistropy is insufficient to explain the canted antiferromagnetism.