Magnetic hysteresis and refrigeration capacity of Ni-Mn-Ga alloys near Martensitic transformation  

作　　者：傅斌 龙毅 段静芳 王超伦 常永勤 叶荣昌 吴光恒 

机构地区：[1]School of Materials Science and Engineering,University of Science and Technology Beijing [2]Institute of Physics,Chinese Academy of Sciences

出　　处：《Chinese Physics B》2010年第9期576-579,共4页中国物理B（英文版）

基　　金：supported by the National Basic Research Program of China (Grant No.2006CB601101);the National High Technology Research and Development Program of China (Grant No.2007AA03Z440);the National Natural Science Foundation of China(Grant No.50731007)

摘　　要：This paper studies the magnetic hysteresis and refrigeration capacity of Ni-Mn-Ga alloys in detail during heating and cooling isothermal magnetisation processes. The Ni-Mn-Ga alloys show larger magnetic hysteresis when they trans-form from austenite to martensite, but smaller magnetic hysteresis when they transform from martensite to austenite. This behaviour is independent of either the pure Ni-Mn-Ga alloys or the alloys doped with other elements. Because of the existence of the magnetic hysteresis, the relation between the magnetic entropy change and refrigeration capacity is not simply linear. For practical consideration, magnetocaloric effect of Ni-Mn-Ga alloys should be investigated both on cooling and heating processes.This paper studies the magnetic hysteresis and refrigeration capacity of Ni-Mn-Ga alloys in detail during heating and cooling isothermal magnetisation processes. The Ni-Mn-Ga alloys show larger magnetic hysteresis when they trans-form from austenite to martensite, but smaller magnetic hysteresis when they transform from martensite to austenite. This behaviour is independent of either the pure Ni-Mn-Ga alloys or the alloys doped with other elements. Because of the existence of the magnetic hysteresis, the relation between the magnetic entropy change and refrigeration capacity is not simply linear. For practical consideration, magnetocaloric effect of Ni-Mn-Ga alloys should be investigated both on cooling and heating processes.

关 键 词：magnetic refrigeration capacity first-order magnetic transition Heusler alloys 

分 类 号：TG146.21[一般工业技术—材料科学与工程]