First-order phase transition at the curie temperature in MnAs and MnAs 0.9Sb0.1

Fumihiro Ishikawa, Keiichi Koyama, Kazuo Watanabe, Tetsuya Asano, Hirofumi Wada

研究成果: Article査読

18 被引用数 (Scopus)


Structural transformations of MnAs and MnAs0.9Sb0.1 were investigated by X-ray diffraction in high magnetic fields up to 5 T. The temperature dependence of the magnetization was measured in a magnetic field of 0.01 T and the Curie temperature TC was determined to be 315 K for MnAs and 290 K for MnAs0.9Sb0.1 during heating process. For both compounds, a metamagnetic transition from a paramagnetic to a ferromagnetic state was observed above TC. The X-ray diffraction profile at 319 K for MnAs showed a single phase of an orthorhombic MnP-type structure in zero field. An applied magnetic field of 3 T induced the appearance of a hexagonal NiAs-type structure. On further increase of the magnetic field, a single phase with a hexagonal structure was realized above 3.5 T in a forced-ferromagnetic state. The X-ray diffraction profile at 295 K for MnAs 0.9Sb0.1 showed a hexagonal NiAs-type structure. The coexistence of ferromagnetic and paramagnetic states with different lattice parameters was confirmed in a magnetic field of 2.5 T. The volume expansion induced by a magnetic field was found to be 2.1% for MnAs and 1.1% for MnAs 0.9Sb0.1.

ジャーナルjournal of the physical society of japan
出版ステータスPublished - 2006 8月

ASJC Scopus subject areas

  • 物理学および天文学(全般)


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