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arXiv · 2610.20883

Sb-5$p$-mediated antiparallel Nd-Fe coupling in Nd$_3$Fe$_3$Sb$_7$

S. Palazzese·Sh. Yamamoto·T. Kotte·R. Ray·F. Pabst·S. Chattopadhyay·D. I. Gorbunov·T. Herrmannsdörfer·K. Kummer·A. Kurtanidze·E. Weschke·O. Prokhnenko·K. Yamamoto·Y. Kotani·H. Nojiri·M. Ruck·Manuel Richter·J. Wosnitza
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Abstract

We uncover the microscopic mechanism underlying the antiparallel Nd-Fe coupling in the intermetallic 4$f$-3$d$-5$p$ compound Nd$_3$Fe$_3$Sb$_7$ by means of high-field x-ray magnetic circular dichroism (XMCD) spectroscopy, complemented by magnetization measurements and density-functional-theory (DFT) calculations. This coupling is unexpected for intermetallics composed of light rare-earth and transition-metal elements. Sb $M_{4,5}$-edge XMCD measurements indicate a clear spin polarization of Sb 5$p$ states antiparallel to the Fe 3$d$ moments. DFT calculations reveal the site-dependent character of the Sb moments and, together with the Fe-Sb antiparallel alignment seen by XMCD, identify a Fe 3$d$-Sb 5$p$-Nd 5$d$ hybridization pathway for the antiparallel Nd-Fe coupling. Pulsed-field XMCD reveals a field-induced spin reorientation through the evolution of the $c$-axis projections of the Nd and Fe moments. Nd$_3$Fe$_3$Sb$_7$, thus, provides a platform for exploring antiparallel rare-earth-transition-metal ($R$-$T$) coupling mediated by transition-metal 3$d$-ligand $p$-rare-earth 5$d$ hybridization in light-$R$-$T$ intermetallics with $p$-elements.

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S. Palazzese, Sh. Yamamoto, T. Kotte, R. Ray, F. Pabst, S. Chattopadhyay, D. I. Gorbunov, T. Herrmannsdörfer, K. Kummer, A. Kurtanidze, E. Weschke, O. Prokhnenko, K. Yamamoto, Y. Kotani, H. Nojiri, M. Ruck, Manuel Richter, J. Wosnitza. 2026-10-14. Sb-5$p$-mediated antiparallel Nd-Fe coupling in Nd$_3$Fe$_3$Sb$_7$. https://arxiv.org/abs/2610.20883

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