Ni50.5Mn26.5Ga23單晶磁感生應變的溫度依賴性

By measuring the magnetic-field-induced strain (MFIS) and the transformation strain with a field bias applied in different direction, the temperature dependence of MFIS and the field-controlled shape memory effect in the Ni50.5Mn26.5Ga23 single crystal were investigated. It was found that with decreasing temperature at the martensite phase, the saturated MFIS first decreases rapidly and then the decreasing rate becomes smaller and smaller, reflecting the temperature dependence of the MFIS in the Ni2MnGa system. Moreover, it was also found that the decreasing rate of the saturated MFIS with decreasing temperature is different with a pulse field applied in different direction. The results are discussed with reference to the shape memory characteristics of the alloy and the mechanism of the preferentially orientation of martensitic variants.