%0 Journal Article
%A Staunton, J. B.
%A Banerjee, R.
%A dos Santos Dias, Manuel
%A Deak, A.
%A Szunyogh, L.
%T Fluctuating local moments, itinerant electrons, and the magnetocaloric effect: Compositional hypersensitivity of FeRh
%J Physical review / B
%V 89
%N 5
%@ 1098-0121
%C College Park, Md.
%I APS
%M FZJ-2014-03350
%P 054427
%D 2014
%X We describe an ab initio disordered local moment theory for materials with quenched static compositional disorder traversing first-order magnetic phase transitions. It accounts quantitatively for metamagnetic changes and the magnetocaloric effect. For perfect stoichiometric B2-ordered FeRh, we calculate the transition temperature of the ferromagnetic-antiferromagnetic transition to be Tt= 495 K and a maximum isothermal entropy change in 2 T of |ΔS|=21.1 J K−1 kg−1. A large (40%) component of |ΔS| is electronic. The transition results from a fine balance of competing electronic effects which is disturbed by small compositional changes; e.g., swapping just 2% Fe of “defects” onto the Rh sublattice makes Tt drop by 290 K. This hypersensitivity explains the narrow compositional range of the transition and impurity doping effects.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000332409800002
%R 10.1103/PhysRevB.89.054427
%U https://juser.fz-juelich.de/record/153871