Atomic disorder in Heusler Co 2MnGe measured by anomalous x-ray diffraction

Publication Type:

Journal Article

Authors:

B. Ravel; J.O. Cross; M.P. Raphael; V.G. Harris; Ramamoorthy Ramesh; L.V. Saraf

Source:

Applied Physics Letters, Volume 81, Number 15, p.2812-2814 (2002)

Keywords:

Anomalous X-ray diffraction, Antisite disorder, Atomic disorder, Band theory, carbon dioxide, Cobalt, Conduction electrons, Germanium, Half metallic ferromagnets, Half metals, Heusler, Heusler alloys, High precision, Manganese, spin dynamics, spin polarization, Spin state, Structural defect, Sub-lattices, X ray diffraction

Abstract:

Heusler alloys Co 2MnX, where X is Ge or Si, are predicted by the band theory to be a half-metallic ferromagnets, i.e., metals with all conduction electrons of the same spin state. To date, Heusler alloys have been measured with spin polarizations of 50%-60%, higher than Fe (∼40%), but not a true half metal. Structural defects involving site swapping between the Co and Mn sublattices have been proposed as a mechanism to diminish spin polarization. In this work, we present an anomalous x-ray diffraction measurement on Co 2MnGe to determine antisite disorder in thin films with a high precision. © 2002 American Institute of Physics. © 2002 American Institute of Physics.

Notes:

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