Magnetic anisotropy studies on the cobalt-based chain molecular magnet CoCu(opba)(DMSO)(3)

The present paper reports on a study of the magnetic anisotropy of the Co-b ased chain molecular magnet CoCu(opba)(DMSO)(3). The magnetic anisotropy me asurements were performed on microgram monocrystalline samples using a cant ilever magnetometer at low temperatures down to 1.5 K and magnetic fields u p to 7 T. The field dependence of the magnetic torque confirms an ordered f errimagnetic structure at low temperature, T-C=6 K, with a very small coerc ive field. Magnetic torque measurements as a function of the angle within t he a-c and b-c planes suggest the emergence of biaxial behavior at low temp eratures. Our results suggest that the resulting ferromagnetic moment lies perpendicular to both the CuCo-chains and hard magnetic axis. (C) 2001 Else vier Science BY. All rights reserved.