Interface characterization of Co2MnGe/Rh2CuSn Heusler multilayers

: Ronny Knut, Peter Svedlindh, Oleg Mryasov, Klas Gunnarsson, Peter Warnicke, D A Arena, Matts Björck, Andrew J C Dennison, Anindita Sahoo, Sumanta Mukherjee, D D Sarma, Sari Granroth, Mihaela Gorgoi, Olof Karis

Publisher: AMER PHYSICAL SOC

: COLLEGE PK; ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA

: 2013

: Physical Review B

: Phys.Rev.B

: 13

: 88

: 13

: 134407

: 8

: 1098-0121

DOI: https://doi.org/10.1103/PhysRevB.88.134407

To address the amount of disorder and interface diffusion induced by annealing, all-Heusler multilayer structures, consisting of ferromagnetic Co2MnGe and nonmagnetic Rh2CuSn layers of varying thicknesses, have been investigated by means of hard x-ray photoelectron spectroscopy and x-ray magnetic circular dichroism. We find evidence for a 4 angstrom thick magnetically dead layer that, together with the identified interlayer diffusion, are likely reasons for the unexpectedly small magnetoresistance found for current-perpendicular-to-plane giant magnetoresistance devices based on this all-Heusler system. We find that diffusion begins already at comparably low temperatures between 200 and 250 degrees C, where Mn appears to be most prone to diffusion.