High field X-ray diffraction studies on magnetic refrigerants

Issue title: Second INABIO Symposium, 2005

Article type: Research Article

Authors: Koyama, Keiichi^{a; *} | Ishikawa, Fumihiro^a | Watanabe, Kazuo^a

Affiliations: [a] High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan

Correspondence: [*] Corresponding author: Keiichi Koyama, E-mail: kkoyama@imr.tohoku.ac.jp

Abstract: In this paper, we review our recent results on magnetic refrigerants MnAs_{1-x}Sb_{x} and MnFeAs_{0.5}P_{0.5} by powder X-ray diffraction measurements in fields up to 5 T and in the temperature range from 8 to 320 K. MnAs shows a first-ordered structural transition with the volume expansion of 2.1% accompanied by a metamagnetic transition, but MnAs_{0.9}Sb_{0.1} exhibits an isostructural transition with the volume expansion of 1.1%. The cell volume of MnFeAs_{0.5}P_{0.5} slightly (−0.4%) and continuously decreases with increasing a magnetic field through the metamagnetic transition.

Keywords: High field X-ray diffraction, field-induced phase transition, magnetovolume effect, magnetic refrigerant

DOI: 10.3233/JAE-2006-734

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 23, no. 3-4, pp. 153-163, 2006