Suppression of martensitic phase transition at the Ni2 MnGa film surface

Journal Article

Pörsch, P, M Kallmayer, T Eichhorn, G Jakob, H.J Elmers, C.A Jenkins, C Felser, Ramamoorthy Ramesh, M Huth

10.1063/1.2957647

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.

Applied Physics Letters

93

2008

00036951

cited By 18

Ramesh Lab