Ni_(52)Mn_(24)Ga_(24)单晶中取向内应力的热动力学计算  

Thermodynamic calculation of the oriented internal stress in single crystals of Ni_(52)Mn_(24)Ga_(24)

作　　者：崔玉亭[1,2] 柳祝红[1] 王文洪[1] 张铭[1] 陈京兰[1] 王万录[3] 吴光恒[1] 孟凡斌[4] 曲静萍[4] 李养贤[4] 

机构地区：[1]中国科学院物理研究所磁学国家重点实验室 [2]重庆大学应用物理系,重庆400044 [3]重庆大学应用物理系 [4]河北工业大学磁性材料与技术中心

出　　处：《物理学报》2003年第7期1726-1731,共6页Acta Physica Sinica

基　　金：国家自然科学基金 (批准号 :5 0 13 10 10 )资助的课题~~

摘　　要：测量了Ni52 Mn2 4 Ga2 4 单晶样品在磁场加载和未加载情况下马氏体相变时的相变应变 .分析结果表明 :用提拉法生长单晶时在晶体内部引入了单一取向的内应力 ,该取向内应力可诱导马氏体变体择优取向 ,从而导致马氏体相变时产生大的相变应变 .从理论上计算了该内应力的大小 .另外 ,对样品在马氏体态单纯磁诱导应变的热动力学研究 ,表明取向内应力在马氏体态依然存在 .The internal stress in single crystals of Ni52Mn24Ga24 has been calculated based on the balance equation and the experimental data on transformation strains with or without bias field. It was found that the residual oriented internal stress caused by the directional solidification during the crystal growth plays an important role in achieving the reorientation of the variants, and resulting in a large transformation strain. Furthermore, according to Maxwell equation and Ullako's thermal dynamic model, the theoretical value of magnetic-field-induced strains and internal stress at different temperatures in martensite was calculated based on a best fitting of the strain curves versus the bias field. Compared with the experimental observation, the availability of various models has been discussed.

关 键 词：马氏体相变 磁感生应变 内应力 Ni52Mn24Ga24单晶 热动力学计算 相变应变 哈斯勒合金 提拉法 单晶生长 

分 类 号：TG111[金属学及工艺—物理冶金]