哈斯勒合金Ni50Mn35In15的马氏体相变及其磁热效应

利用电弧炉熔炼了Ni₅₀Mn₃₅In₁₅多晶样品，根据磁性测量对其马氏体相变和磁热效应进行了系统研究.结果表明，随着温度的降低，样品在室温附近先后发生了二级磁相变与一级结构相变特征的马氏体相变，导致它的磁化强度产生突变. 同时通过低温下的磁滞回线的测量发现样品存在交换偏置行为，表明低温下马氏体相中铁磁和反铁磁共存. 此外，根据Maxwell方程，计算了样品在马氏体相变温度附近的磁熵变，当温度为309K，磁场改变5 T时，样品的磁熵变可达22.3J/kgK. 关键词： 哈斯勒合金 50Mn₃₅In₁₅')" href="#">Ni₅₀Mn₃₅In₁₅ 马氏体相变 磁热效应

Martensitic transformation and magnetocaloric effect in Ni50Mn35In15 Heusler alloy

Polycrystalline Ni₅₀Mn₃₅In₁₅ alloy was fabricated by arc-melting, and its martensitic transformation and magnetocaloric effect were systematically investigated with magnetic property measurement. The experimental results indicated that, with decrease of temperature, the second-order magnetic transition and the martensitic transition with characteristic of the first-order structural transition happened successively near room temperature, leading to an abrupt change of magnetization. At the same time, exchange bias was found by means of hysteresis loop measurement at low temperature, which clearly suggested coexistence of ferromagnetic and anti-ferromagnetic phases at low temperatures. In addition, a large magnetic entropy change during martensitic transition was calculated from Maxwell equations. Its value can reach 22.3 J/kg K at 309K in applied field of 5T.