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arXiv · 1205.0604

Quenched Fe Moment in the Collapsed Tetragonal Phase of Ca$_{1-x}$Pr$_{x}$Fe$_2$As$_2$

Long Ma·G. F. Ji·J. Dai·S. R. Saha·J. Paglione·Weiqiang Yu
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Abstract

We report $^{75}$As NMR studies on single crystals of rare-earth doped iron pnictides superconductor Ca$_{1-x}$Pr$_{x}$Fe$_{2}$As$_{2}$ ($x$=0.075 and 0.15). The $^{75}$As spectra show a chemical pressure effect with doping and a first order structure transition to the collapsed tetragonal phase upon cooling. A sharp drop of the Knight shift is seen below the structural transition, whereas $1/T_1$ is strongly enhanced at low-temperatures. These evidences indicate quenching of Fe local magnetism and short-range ordering of Pr$^{3+}$ moment in the collapsed tetragonal phase. The quenched Fe moment through structure collapse suggests a strong interplay of structure and magnetism, which is important for understanding the nature of the collapsed tetragonal phase.

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Long Ma, G. F. Ji, J. Dai, S. R. Saha, J. Paglione, Weiqiang Yu. 2012-05-03. Quenched Fe Moment in the Collapsed Tetragonal Phase of Ca$_{1-x}$Pr$_{x}$Fe$_2$As$_2$. https://doi.org/10.1088/1674-1056%2F22%2F5%2F057401

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