The structural phase transition induced by magnetic fields on MnAs was observed by the X-ray diffraction measurements in high magnetic fields up to 4 T. Magnetization measurements showed that Curie temperature TC was 315.5 K for increasing temperatures and a metamagnetic transition from the paramagnetic to the ferromagnetic state occurred above TC. The structural transformation from the hexagonal NiAs-type to the orthorhombic MnP-type structure was confirmed at TC with increasing temperature from 290 to 319 K via two-phase coexistence region. The X-ray diffraction profiles at 319 K showed the single phase of the MnP-type structure in zero field and applying magnetic field of 3 T caused appearance of the Brag peak of the hexagonal structure. On further increase of magnetic fields, the single phase of the hexagonal structure was observed above 3.5 T in the forced ferromagnetic state. Both the magnetic and structural transitions induced by magnetic fields above TC were first order with a hysteresis and had a close relationship between each other.
|ジャーナル||Physica B: Condensed Matter|
|出版ステータス||Published - 2004 4 30|
|イベント||Proceedings of the 7th International Symposium on Research - Toulouse, France|
継続期間: 2003 7 20 → 2003 7 23
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