We have studied polycrystalline Yb4LiGe4, a ternary variant of the R5T4 family of layered compounds characterized by a very strong coupling between the magnetic and crystallographic degrees of freedom. The system is mixed valent, with non-magnetic Yb2+ and magnetic Yb3+ present, and is characterized by coexisting ferromagnetic and antiferromagnetic correlations. We present measurements of resistivity, AC-susceptibility, specific heat, and muon spin relaxation (muSR), below 1 K. The low temperature measurements suggest a transition to a mesoscopically inhomogeneous magnetically ordered state below 2 K characterized by fluctuations well below the ordering temperature. This unusual state is believed to result from the enhanced two-dimensionality produced by Li substitution and frustration effects inherent in the Yb sub-lattice geometry.
@article{arxiv.1110.0118,
title = {Competing Interactions and Magnetic Frustration in Yb4LiGe4},
author = {S. M. Disseler and J. N. Svensson and S. C. Peter and C. P. Byers and C. Baines and A. Amato and S. R. Giblin and P. Carretta and M. J. Graf},
journal= {arXiv preprint arXiv:1110.0118},
year = {2012}
}
Comments
29 pages, 11 figures, accepted for publication, Physical Review B