The influence of gadolinium on magnetism and magnetocaloric properties of HoCo2 alloy

• Published in: Journal of alloys and compounds Vol. 455; no. 1-2; pp. 73 - 76
• Main Authors: BALLI, M, FRUCHART, D, GIGNOUX, D
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier 08.05.2008
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.); Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Magnetocaloric effect, magnetic cooling; Physics; Landau theory; Curie point; Magnetization; Ternary alloys; Entropy; XRD; Magnetic transitions; Gadolinium alloys; 75.10.Lp; 75.30.Sg; Magnetocaloric effects; Ho1-xGdxCo2; Magnetocaloric effect; Magnetic refrigeration; Holmium alloys; Ordering; Cobalt alloys; Crystal growth from melts; Transition element alloys; Crystal structure
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2007.01.110

A series of Ho1-xGdxCo2 (x = ,0.,0.,0.,0.,0.,0.8, 1) samples were prepared by arc-melting method. The crystal structure, magnetic and magnetocaloric effect were investigated by X-ray powder diffraction and magnetization measurements. Then the magnetic phase transition was analyzed in term of Landau theory. The experimental results indicate that the ordering temperature TC increases from 81 to 402 K with increasing Gd substitution so that TC of the alloy is near room temperature (300 K) when x = 0.6. This Curie temperature increase is accompanied by a reduction of entropy change -DeltaS. For an external magnetic field change from 0 to 5 T, -DeltaS at TC is 11, 4.65 and 3 J/(kg K) for x = 0.,0.3 and 0.6, respectively. The origin and the evolution of magnetocaloric effect in Ho1-xGdxCo2 compounds are discussed.