Element specific investigation of ultrathin Co[sub 2]MnGa¨MGaAs heterostructures

DOI: 10.1063/1.2712165

Authors: Jill S. Claydon (Electronics Department, University of York, U.K.) , Sameh Hassan (Electronics Department, University of York, U.K.) , Christian D. Damsgaard (Department of Physics and Department of Micro and Nanotechnology, Technical University of Denmark, Denmark.) , Jorn Bindslev Hansen (Department of Physics, Technical University of Denmark, Denmark) , Claus S. Jacobsen (Department of Physics, Technical University of Denmark, Denmark) , Yongbing Xu (University of York) , Gerrit Van Der Laan (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Applied Physics , VOL 101 (9)

State: Published (Approved)
Published: May 2007

Abstract: We have used x-ray magnetic circular dichroism to study the element specific magnetic properties of ultrathin films of the Heusler alloy Co 2 MnGa Co2MnGa at room temperature. Nine films were grown by molecular beam epitaxy on GaAs substrates and engineered to vary in stoichiometry as Co 1.86 Mn 0.99 Ga 1 Co1.86Mn0.99Ga1 , Co 1.95 Mn 0.98 Ga 1 Co1.95Mn0.98Ga1 , and Co 1.97 Mn 0.96 Ga 1 Co1.97Mn0.96Ga1 , with thicknesses of 5.3, 7.6, and 9.7nm 9.7nm , and were capped with Al to prevent oxidization. Sum rule analysis revealed magnetic moments significantly lower than the values predicted theoretically, especially in the case of the Mn total magnetic moment. The results do not support the hypothesis that a large magnetic moment is transferred from Co to Mn, and may suggest that diffusion and reacted layers at ultrathin thicknesses can effect the establishment of a full Heusler structure.

Journal Keywords: cobalt alloys; manganese alloys; gallium alloys; metallic epitaxial layers; magnetic epitaxial layers; magnetic circular dichroism; magnetic moments; stoichiometry; ferromagnetic materials

Subject Areas: Physics

Facility: Daresbury