Ferrimagnetism and disorder in epitaxial Mn(2-x)Co(x)VAl thin films

Abstract

The quaternary full Heusler compound Mn(2-x)Co(x)VAl with x = 1 is predicted to be a half-metallic antiferromagnet. Thin films of the quaternary compounds with x = 0...2 were prepared by DC and RF magnetron co-sputtering on heated MgO (001) substrates. The magnetic structure was examined by x-ray magnetic circular dichroism and the chemical disorder was characterized by x-ray diffraction. Ferrimagnetic coupling of V to Mn was observed for Mn2VAl (x = 0). For x = 0.5, we also found ferrimagnetic order with V and Co antiparallel to Mn. The observed reduced magnetic moments are interpreted with the help of band structure calculations in the coherent potential approximation. Mn2VAl is very sensitive to disorder involving Mn, because nearest-neighbor Mn atoms couple anti-ferromagnetically. Co2VAl has B2 order and has reduced magnetization. In the cases with x >= 0.9 conventional ferromagnetism was observed, closely related to the atomic disorder in these compounds.

arXiv comment10 pages, 4 figures

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Cited by in corpus (11)

• New iron-based Heusler compounds Fe2YZ: Comparison with theoretical predictions of the crystal structure and magnetic properties
• Itinerant and local magnetic moments in ferrimagnetic Mn2CoGa thin films probed by x-ray magnetic linear dichroism: experiment and ab initio theory
• Adjacent Fe-Vacancy Interactions as the Origin of Room Temperature Ferromagnetism in (In${}_{1-x}$Fe${}_x$)${}_2$O${}_3$
• Electronic Structure and Magnetic Properties of Half-metallic Ferrimagnet Mn${}_2$VAl Probed by Soft X-ray Spectroscopies
• Ferromagnetic structures in Mn2CoGa and Mn2CoAl doped by Co, Cu, V, and Ti
• Evidence for Localized Moment Picture in Mn-based Heusler Compounds
• Magnetic properties of strained multiferroic CoCr2O4: a soft X-ray study
• Half-metallicity of Mn2VAl ferrimagnet revealed by resonant inelastic soft x-ray scattering under magnetic field
• Negative spin polarization of Mn2VGa probed by tunnel magnetoresistance
• Soft x-ray absorption of thin films detected using substrate luminescence: A performance analysis
• Mn${}_2$VAl Heusler alloy thin films: Appearance of antiferromagnetism and an exchange bias in a layered structure with Fe