화학공학소재연구정보센터
Journal of Crystal Growth, Vol.312, No.9, 1651-1658, 2010
Magnetic properties of Gd4Y3Pd3 single crystal
Gd4Y3Pd3 belongs to Gd7-xYxPd3 series examined as prospective materials for magnetic refrigeration. Single crystal of Gd4Y3Pd3 was grown by the Czochralski method from a levitated melt. Investigations of X-ray diffraction, electronic structure, dc-magnetization M(T), ac-magnetic susceptibility (ac-chi) and electrical resistivity (rho) for the hexagonal Th7Fe3-type for Gd4Y3Pd3 single crystal were performed. ac-chi(T) and M(T) measurements have allowed to establish that Gd4Y3Pd3 undergoes a long-range ferromagnetic ordering at T-C=240 K, followed by a spin-reorientation below 160 K. The magnetization data indicate that there is an excess magnetic moment calculated per Gd3+ ions. The measured XPS valence band indicates the hybridization effect between Gd 5d, Y4d and Pd 4d states. The fitting of the XPS Y3d line and the powder X-ray diffraction spectrum shows the location of yttrium atoms in three nonequivalent gadolinium positions. Magnetic and electrical resistivity behaviour points to the coexistence of localized magnetism from the magnetic Gd3+ ions and itinerant ferromagnetism from 4d- and 5d-electron bands. The changes of magnetic frustration after yttrium substitution also influence the magnetic properties. (C) 2010 Elsevier B.V. All rights reserved.