We have characterized the magnetic and structural properties of the CdLn2Se4 (Ln = Dy, Ho), and CdLn2S4 (Ln = Ho, Er, Tm, Yb) spinels. We observe all compounds to be normal spinels, possessing a geometrically frustrated sublattice of lanthanide atoms with no observable structural disorder. Fits to the high temperature magnetic susceptibilities indicate these materials to have effective antiferromagnetic interactions, with Curie-Weiss temperatures theta ~ -10 K, except CdYb2S4 for which theta ~ -40 K. The absence of magnetic long range order or glassiness above T = 1.8 K strongly suggests that these materials are a new venue in which to study the effects of strong geometrical frustration, potentially as rich in new physical phenomena as that of the pyrochlore oxides.
@article{arxiv.cond-mat/0504422,
title = {Geometrical Magnetic Frustration in Rare Earth Chalcogenide Spinels},
author = {G. C. Lau and R. S. Freitas and B. G. Ueland and P. Schiffer and R. J. Cava},
journal= {arXiv preprint arXiv:cond-mat/0504422},
year = {2009}
}