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arXiv · 1508.07495

Magnetic properties of Gd$T_2$Zn$_{20}$ (T = Fe, Co) investigated by X-ray diffraction and spectroscopy

J. R. L. Mardegan·G. Fabbris·L. S. I. Veiga·S. Francoual·J. Strempfer·D. Haskel·R. A. Ribeiro·M. A. Avila·C. Giles
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Abstract

We investigate the magnetic and electronic properties of the Gd$T_2$Zn$_{20}$ ($T$ = Fe and Co) compounds using X-ray resonant magnetic scattering (XRMS), X-ray absorption near-edge structure (XANES) and X-ray magnetic circular dichroism (XMCD) techniques. The XRMS measurements reveal that the GdCo$_2$Zn$_{20}$ compound has a commensurate antiferromagnetic spin structure with a magnetic propagation vector $\vecτ$ = $(\frac{1}{2},\frac{1}{2},\frac{1}{2})$ below the Néel temperature ($T_N \sim$ 5.7 K). Only the Gd ions carry a magnetic moment forming an antiferromagnetic structure with magnetic representation $Γ_6$. For the ferromagnetic GdFe$_2$Zn$_{20}$ compound, an extensive investigation was performed at low temperature and under magnetic field using XANES and XMCD techniques. A strong XMCD signal of about 12.5 $\%$ and 9.7 $\%$ is observed below the Curie temperature ($T_C \sim$ 85 K) at the Gd-$L_2$ and $L_3$ edges, respectively. In addition, a small magnetic signal of about 0.06 $\%$ of the jump is recorded at the Zn $K$-edge suggesting that the Zn 4$p$ states are spin polarized by the Gd 5$d$ extended orbitals.

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J. R. L. Mardegan, G. Fabbris, L. S. I. Veiga, S. Francoual, J. Strempfer, D. Haskel, R. A. Ribeiro, M. A. Avila, C. Giles. 2015-08-29. Magnetic properties of Gd$T_2$Zn$_{20}$ (T = Fe, Co) investigated by X-ray diffraction and spectroscopy. https://doi.org/10.1103/physrevb.93.024421

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