Magnetic ordering in KDy3F10:: A system containing three orthogonal Ising lattices -: art. no. 134414

The rare-earth fluorides with KY3F10 structure are cubic, with three nonequivalent sites for the rare-earth ion, each with a tetragonal symmetry axis aligned along one of the three cubic axes. We present magnetic susceptibility and magnetization results for KDy3F10, a material which displays nearly complete (Ising) anisotropy of the magnetic moments along the local symmetry axis. Magnetic exchange is antiferromagnetic, and the dipole-dipole interaction favors antiferromagnetism in the absence of exchange. Despite this, we observe a spontaneously polarized magnetic state at low temperature. The explanation appears to lie in the relative magnitudes of the two interactions.