TY - JOUR
T1 - Delocalization and hybridization enhance the magnetocaloric effect in Cu-doped Ni2MnGa
AU - Roy, S
AU - Blackburn, Elizabeth
AU - Valvidares, SM
AU - Fitzsimmons, MR
AU - Vogel, SC
AU - Khan, M
AU - Dubenko, I
AU - Stadler, S
AU - Ali, N
AU - Sinha, SK
AU - Kortright, JB
PY - 2009/6/1
Y1 - 2009/6/1
N2 - The structural and magnetic transitions in the shape-memory alloy Ni2MnGa can be tuned as a function of temperature by adding dopants. By altering the free energy such that the structural and magnetic transitions coincide, a giant magnetocaloric effect is created near room temperature. We show, using x-ray absorption spectroscopy and x-ray magnetic circular dichroism, how Cu, substituted for Mn, pulls the magnetic transition downward in temperature and also, counterintuitively, increases the delocalization of the Mn magnetism. At the same time, this reinforces the Ni-Ga chemical bond, raising the temperature of the martensite-austenite transition. At 25% doping, the two transitions coincide at 317 K.
AB - The structural and magnetic transitions in the shape-memory alloy Ni2MnGa can be tuned as a function of temperature by adding dopants. By altering the free energy such that the structural and magnetic transitions coincide, a giant magnetocaloric effect is created near room temperature. We show, using x-ray absorption spectroscopy and x-ray magnetic circular dichroism, how Cu, substituted for Mn, pulls the magnetic transition downward in temperature and also, counterintuitively, increases the delocalization of the Mn magnetism. At the same time, this reinforces the Ni-Ga chemical bond, raising the temperature of the martensite-austenite transition. At 25% doping, the two transitions coincide at 317 K.
U2 - 10.1103/PhysRevB.79.235127
DO - 10.1103/PhysRevB.79.235127
M3 - Article
SN - 1098-0121
VL - 79
SP - 235127
JO - Physical Review B
JF - Physical Review B
IS - 23
ER -