Phase analysis of Gd5(SixGe1−x)4 alloys prepared from different purity Gd with x=0.475 and 0.43

Received 8 September 2004; received in revised form 28 January 2005; accepted 30 January 2005.

Abstract

The magnetocaloric effect materials Gd5(SixGe1−x)4 with x=0.475 and 0.43 based on 99.94wt% and 99.2wt% purity Gd have been synthesized and their phase components have been investigated by X-ray diffraction, scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). According to the X-ray powder diffraction analysis, Gd5Si1.9Ge2.1 with high purity Gd is Gd5Si2Ge2-type single-phase, whereas Gd5Si1.72Ge2.28 with high purity Gd presents Gd5Si2Ge2-type and GdGe-type phases. On the other hand, Gd5Si2Ge2-type, Gd5Si3-type, and GdGe-type multi-phases have been found in both Gd5Si1.9Ge2.1 and Gd5Si1.72Ge2.28 with low purity Gd. In addition, SEM clearly shows the three discernible phases in the alloys with low purity Gd; EDS analyses have been conducted on all of them.

Keywords: Rare earth, Gd5(SixGe1−x)4 alloys, X-ray powder diffraction, Scanning electron microscopy

School of Materials Science and Engineering, Sichuan University, 24, Southern Section 1, 1st Ringroad, Chengdu 610064, China

Corresponding author. Tel.: +86 288 540 5670; fax: +86 288 540 7335

PII: S1359-6454(05)00074-1

doi:10.1016/j.actamat.2005.01.045

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