@article{33579, keywords = {Nickel, Nickel alloys, Magnetic (CE), Martensitic phase transitions}, author = {P Pörsch and M Kallmayer and T Eichhorn and G Jakob and H.J Elmers and C.A Jenkins and C Felser and Ramamoorthy Ramesh and M Huth}, title = {Suppression of martensitic phase transition at the Ni2 MnGa film surface}, abstract = {We investigated magnetic and structural properties at the surface of epitaxial Ni2 MnGa (110) Heusler films using x-ray absorption spectroscopy and x-ray magnetic circular dichroism both in transmission and total electron yield mode. The magnetic shape memory films were prepared by dc sputtering from a stoichiometric target onto sapphire substrates at an optimized substrate temperature of 773 K. X-ray diffraction confirms a (110) oriented growth on Al2 O3 (11 2- 0) and an austenite to martensite transition at 270-280 K. At the surface the martensitic phase transition and the magnetization are strongly suppressed. The deviation in the surface properties is caused by a Mn deficiency near the surface. © 2008 American Institute of Physics.}, year = {2008}, journal = {Applied Physics Letters}, volume = {93}, number = {2}, issn = {00036951}, doi = {10.1063/1.2957647}, note = {cited By 18}, language = {eng}, }