DocumentCode :
766493
Title :
The Overlap of First- and Second-Order Phase Transitions and Related Magnetic Entropy Changes in Ni 
Mn 
Ga Heusler Alloys
Mn Ga Heusler AlloysAuthor :
Khan, Mahmud ; Stadler, Shane ; Craig, Jonathan ; Mitchell, Joseph ; Ali, Naushad
Author_Institution :
Dept. of Phys., Southern Illinois Univ.
Volume :
42
Issue :
10
fYear :
2006
Firstpage :
3108
Lastpage :
3110
Abstract :
A study of the magnetostructural phase transition and related magnetic entropy changes, DeltaSM, in the vicinity of a first-order magnetostructural transition, in polycrystalline shape memory alloys Ni2+xMn1-x Ga (x=0.16,0.17,0.18,0.19,0.20) have been done. Thermal expansion measurements reveal the gradual overlap of the first- and second-order phase transitions that results in the large magnetic entropy changes in the alloys. We observed a magnetic entropy change of DeltaSM=-66.2 J/kg-1middotK-1 between 350 K and 350.5 K in a field change of 5 T in Ni2+xMn 1-x Ga for x=0.19
Keywords :
entropy; magnetic transitions; manganese alloys; nickel alloys; shape memory effects; thermal expansion measurement; 5 T; Heusler alloys; Ni2MnGa; first-order phase transitions; magnetic entropy; magnetostructural phase transition; polycrystalline shape memory alloys; second-order phase transitions; thermal expansion measurements; Entropy; Gallium alloys; Magnetic field measurement; Magnetic materials; Manganese alloys; Nickel alloys; Phase measurement; Shape memory alloys; Superconducting magnets; Temperature; Magnetic materials; magnetoelasticity;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.2006.879632
Filename :
1704542
Link To Document :
