engleski

Magnetic properties of Cu3TeO6 - system with novel spin lattice

Cu3TeO6 is an insulating cubic compound that possesses a new kind of three – dimensional spin lattice [1]. This lattice is composed of Cu2+ spins S=1/2 which make almost planar hexagons. Each hexagon shares vertices with six other hexagons thus forming a three-dimensional spin lattice. This lattice can be compared to the one of isolated Cu2+ S=1/2 hexagons in Cu3WO6 which leads to spin singlet ground state in that compound [2]. Cu3TeO6, however, orders antiferromagnetically (AFM) below TN = 61 K. Curie-Weiss temperature obtained from dc susceptibility in the paramagnetic regime is Θ CW = - 148 K which suggests strong AFM correlations between spins. Neutron powder diffraction reveals that AFM long range order is associated with wave vector k = (0, 0, 0). In ordered state the dominant component of the magnetic moment is along one of the <± 1 ± 1 ± 1> space diagonals of the unit cells [1]. This leads to the spontaneous formation of four AFM domains. Above TN the system is magnetically isotropic, while below TN a large field dependent magnetic anisotropy develops, as observed from the torque magnetometry. In magnetic fields ≥ 500 Oe the switching of domains is induced. The dynamics related to the movement of domain walls is very slow at low temperatures (≈ 10^2 s).

magnetism; spin lattice; domains

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