NiMnGa合金的大磁致应变是在具有单变体结构的单晶中获得的。目前，国际上普遍采用单向压缩工艺获得单变体。但是，对较大长径比样品，由于此工艺会造成弯曲变形，不可能通过压缩进行单变体处理。本文报道了一种用强磁场处理的方法，进行NiMnGa单晶的单变体处理。采用光子加热悬浮区熔法，制备了Ф7×38.9 mm的Ni50Mn28.5Ga21.5合金单晶。通过10T脉冲磁场反复磁化的方法，对单晶样品进行变体处理，获得近似单变体，并获得了5.2％的大磁致应变。研究了磁致应变的压力效应，结果表明随压应力增大，孪晶再取向的临界磁场强度增大，饱和磁致应变降低。
The giant magnetostrain of NiMnGa alloys have been gained only in the single crystals with a single variant structure. Uniaxial compression treatments were used generally to get the single variant. But the method could not treat the samples with large length-diameter radios by reason of causing bend deformation. In this paper, high magnetic field treatment on the NiMnGa single crystals to gain a single variant is reported. Ni50Mn28.5Ga21.5 single crystal with size of Ф7×38.9 mm was prepared by optical floating zone-melting method. The single crystal was magnetized repeatedly in a 10T pulsed magnetic field for martensite variants treatment, and a near single variant with 5.2% giant magnetostrain was obtained. The pressure effect on the magnetostrain was investigated, and the results showed that with the compression stress increasing, the critical magnetic field for the magnetostrain jump was increased and the saturated magnetostrain was decreased.
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| [4] |
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