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arXiv · 1004.5182

Spin Glass ground state in Mn$_{1-x}$Co$_{x}$Si

J. Teyssier·E. Giannini·V. Guritanu·R. Viennois·D. van der Marel·A. Amato·S. N. Gvasaliya
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Abstract

We report the discovery of a new spin glass ground state in the transition metal monosilicides with the B20 crystallographic structure. Magnetic, transport, neutron and muon investigation of the solid solution Mn$_{1-x}$Co$_{x}$Si have revealed a new dome in the phase diagram with evidence of antiferromagnetic interactions. For Mn rich compounds, a sharp decrease of the Curie temperature is observed upon Co doping and neutron elastic scattering shows that helimagnetic order of MnSi persists up to $x=0.05$ with a shortening of the helix period. For higher Co ($0.05<x<0.90$) concentrations, the Curie-Weiss temperature changes sign and the system enters a spin glass state upon cooling ($T_g=9$ K for $x_{Co}=0.50$), due to chemical disorder. In this doping range, a minimum appears in the resistivity, attributed to scattering of conduction electron by localized magnetic moments.

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J. Teyssier, E. Giannini, V. Guritanu, R. Viennois, D. van der Marel, A. Amato, S. N. Gvasaliya. 2010-04-29. Spin Glass ground state in Mn$_{1-x}$Co$_{x}$Si. https://doi.org/10.1103/physrevb.82.064417

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