刘献明
,
付绍云
,
肖红梅
,
李元庆
金属学报
采用聚合－热解法制备了Co0.2Zn0.2Mn0.6Fe2O磁性纳米颗粒, 借助热重分析法(TG)、X射线衍射(XRD)、透射电镜(TEM)和振动样品磁强计(VSM)对产物进行了表征. 结果表明, 产物具有尖晶石结构,无杂相, 粒径分布范围在8-15 nm之间. 常温下该材料的剩磁强度和矫顽力分别为0.516和2.388 kA/m
关键词:
纳米颗粒
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Magnetization
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Ferromagnetism
Shihai GUO
,
Yanghuan ZHANG
,
Jianliang LI
,
Baiyun QUAN
,
Yan QI
,
Xinlin WANG
材料科学技术（英文）
A magnetic shape memory alloy with nonstoichiometric Ni50Mn27Ga23 was prepared by using melt-spinning technology. The martensitic transformation and the magnetic-field-induced strain (MFIS) of the polycrystalline melt-spun ribbon were investigated. The experimental results showed that the melt-spun ribbons underwent thermal-elastic martensitic transformation and reverse transformation in cooling and heating process and exhibited typical thermo-elastic shape memory effect. However the start temperature for martensitic transformation decreased from 286 K for as-cast alloy to 254 K for as-quenched ribbon and Curie temperature remains approximately constant. A particular internal stress induced by melt-spinning resulted in the formation of a texture structure in the ribbons, which made the ribbons obtain larger martensitic transformation strain and MFIS. The internal stress was released substantially after annealing, which resulted in a decrease of MFIS of the ribbons.
关键词:
Shape memory alloy
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