Title :
The overlap of first and second order phase transitions and related magnetic entropy changes in Ni2+xMn1-xGa Heusler alloys
Author :
Khan, M. ; Stadler, S. ; Craig, J. ; Mitchell, J. ; Ali, N.
Author_Institution :
Southern Illinois Univ., Carbondale
Abstract :
In this paper we present a study on the gradual overlap of the first order and second order phase transitions and the related magnetic entropy changes of polycrystalline Ni2+xMn1-xGa (x = 0.16, 0.17,0.18,0.19,0.20). The magnetization measurements were performed on a superconducting quantum interference device (SQUID) made by Quantum Design Inc. X-ray diffraction patterns of Ni2+xMn1-xGa (x =0.16, 0.17, 0.18, 0.19, 0.20) shows that the alloys are single phase and possess the martensitic phase in room temperature. Studies of the magnetostructural transitions and magnetic entropy changes in polycrystalline Ni2+xMn1-xGa (x = 0.17, 0.18, 0.19, 0.20) have been done.
Keywords :
X-ray diffraction; ferromagnetic-paramagnetic transitions; gallium alloys; magnetisation; manganese alloys; martensitic transformations; nickel alloys; Heusler alloys; Ni2MnGa; SQUID; X-ray diffraction; ferromagnetic-paramagnetic transition; first order magnetostructural transition; magnetic entropy; magnetization measurements; martensitic transition; second order phase transition; superconducting quantum interference device; temperature 293 K to 298 K; Entropy; Gallium alloys; Interference; Magnetization; Manganese alloys; Performance evaluation; SQUIDs; Superconducting devices; Superconducting magnets; X-ray diffraction;
Conference_Titel :
Magnetics Conference, 2006. INTERMAG 2006. IEEE International
Conference_Location :
San Diego, CA
Print_ISBN :
1-4244-1479-2
DOI :
10.1109/INTMAG.2006.376396
