Magnetic properties of GdT2Zn20 (T = Fe, Co) investigated by x-ray diffraction and spectroscopy

Abstract

We investigate the magnetic and electronic properties of the GdT2Zn20 (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). The XRMS measurements reveal that GdCo2Zn20 has a commensurate antiferromagnetic spin structure with a magnetic propagation vector (tau) over right arrow = (1/2, 1/2, 1/2) below the Neel temperature (T-N similar to 5.7 K). Only the Gd ions carry a magnetic moment forming an antiferromagnetic structure with magnetic representation Gamma(6). For the ferromagnetic GdFe2Zn20 compound, an extensive investigation was performed at low temperature and under magnetic field using XANES and XMCD. A strong XMCD signal of about 12.5% and 9.7% is observed below the Curie temperature (T-C similar to 85K) 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 4p states are spin polarized by the Gd 5d extended orbitals.