Spin density wave order and fluctuations in Mn3Si: a transport study

Abstract

We present a comprehensive transport investigation of the itinerant antiferromagnet Mn3Si which undergoes a spin density wave (SDW) order below T_N~21.3K. The electrical resistivity, the Hall-, Seebeck and Nernst effects exhibit pronounced anomalies at the SDW transition, while the heat conductivity is phonon dominated and therefore is insensitive to the intrinsic electronic ordering in this compound. At temperatures higher than T_N our data provide strong evidence for a large fluctuation regime which extends up to ~200K in the resistivity, the Seebeck effect and the Nernst effect. From the comparison of our results with other prototype SDW materials, viz. LaFeAsO and Chromium, we conclude that many of the observed features are of generic character.