Electronic structure of the austenitic and martensitic state of magnetocaloric Ni-Mn-In Heusler alloy films
2013 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 88, 174414- p.Article in journal (Refereed) Published
Changes of the electronic and magnetic structure near the martensitic phase transition of Ni-Mn-In Heusler alloys dopedwith Co are investigated by experiment and theory. The nonstoichiometric Ni48Co5Mn35In12 epitaxial film undergoes a transition from a weakly magnetic martensitic phase below T-m = 350 K to a ferromagnetic austenitic phase above T-m. Element-specific magnetic moments and the unoccupied density of states function is investigated using x-raymagnetic circular dichroism.We find an antiparallel alignment ofMnandNi/Comagnetic moments in both phases. The electronic structure is calculated using the SPR-KKR Green's function approach considering experimental results on the atomic disorder in the sample. The good agreement of experimental and theoretically simulated x-ray absorption spectra in both phases confirms that a band Jahn-Teller like lifting of a degenerate d state is the origin of the energetic preference of the martensitic phase at low temperatures.
Place, publisher, year, edition, pages
2013. Vol. 88, 174414- p.
IdentifiersURN: urn:nbn:se:uu:diva-222955DOI: 10.1103/PhysRevB.88.174414ISI: 000327150400008OAI: oai:DiVA.org:uu-222955DiVA: diva2:712532