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arXiv · 1406.6800

Unusual weak magnetic exchange in two different structure types: YbPt$_2$Sn and YbPt$_2$In

Thomas Gruner·Dongjin Jang·Alexander Steppke·Manuel Brando·Franz Ritter·Cornelius Krellner·Christoph Geibel
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Abstract

We present the structural, magnetic, thermodynamic, and transport properties of the two new compounds YbPt$_2$Sn and YbPt$_2$In. X-ray powder diffraction shows that they crystallize in different structure types, the hexagonal ZrPt$_2$Al and the cubic Heusler type, respectively. Despite quite different lattice types, both compounds present very similar magnetic properties: a stable trivalent Yb$^{3+}$, no evidence for a sizeable Kondo interaction, and very weak exchange interactions with a strength below 1K as deduced from specific heat $C(T)$. Broad anomalies in $C(T)$ suggest short range magnetic ordering at about 250mK and 180mK for YbPt$_2$Sn and YbPt$_2$In, respectively. The weak exchange and the low ordering temperature result in a large magnetocaloric effect as deduced from the magnetic field dependence of $C(T)$, making these compounds interesting candidates for magnetic cooling. In addition we found in YbPt$_2$In evidences for a charge density wave transition at about 290K. The occurrence of such transitions within several RET$_2$X compound series (RE = rare earth, T = noble metal, X = In, Sn) is analyzed.

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Thomas Gruner, Dongjin Jang, Alexander Steppke, Manuel Brando, Franz Ritter, Cornelius Krellner, Christoph Geibel. 2014-06-27. Unusual weak magnetic exchange in two different structure types: YbPt$_2$Sn and YbPt$_2$In. https://doi.org/10.1088/0953-8984%2F26%2F48%2F485002

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