Eur. Phys. J. B 55, 77-84 (2007)
https://doi.org/10.1140/epjb/e2007-00042-6

Magnetic structures and crystal field in the heavy electron materials YbAgGe and YbPtIn

¹ Commissariat à l'Énergie Atomique, Centre de Saclay, DSM/SPEC, 91191 Gif-sur-Yvette Cedex, France
² Institute of Physics, Jagiellonian University, 30-059 Kraków, Poland
³ Commissariat à l'Énergie Atomique, Centre de Grenoble, DSM/SPSMS, 38054 Grenoble, France
⁴ Ames Laboratory, Iowa State University, Ames, IA, 50011, USA
⁵ Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany

Corresponding author: ^a bonville@dsm-mail.saclay.cea.fr

Received: 24 October 2006
Revised: 26 January 2007
Published online: 9 February 2007

Abstract

We have examined the magnetic properties of the heavy electron compounds YbAgGe and YbPtIn by ¹⁷⁰Yb Mössbauer spectroscopy down to 0.1 K, and the crystal field properties of YbAgGe by Perturbed Angular Correlations (PAC) measurements up to 900 K. In YbAgGe, we show that each of the two magnetically ordered phases below 0.8 K involves a specific incommensurate modulation of the Yb moment. An analysis of existing low temperature specific heat data suggests the persistence of fluctuations of the correlated Yb spins down to 0.1 K. The PAC data allow to discriminate among proposed Yb³⁺ crystal field level schemes. In YbPtIn, we show that the low temperature magnetic order phase has an antiferro-para structure, where zero moment Yb ions coexist with large moment ones, and that a 90° moment reorientation occurs at 1.4 K.