Reduction of the substitutional disorder by heat treatments in Mn2-xCoxVAl Heusler alloys

Reduction of the substitutional disorder by heat treatments in Mn2-xCoxVAl Heusler alloys

Radu GAVREA, Marin COLDEA, Lucian BARBU-TUDORAN, Olivier ISNARD, Viorel POP. Diana BENEA

download PDF

Abstract. We report on the preparation and the atomic disorder reduction by annealing in Mn2-xCoxVAl Heusler alloys. The degrees of the B2 and L21 atomic ordering for the as-cast samples, obtained from intensity ratios of (200) and (111) peaks respectively related to (220) peak of the X-ray patterns, are significantly improved after annealing at 700 – 800 °C for 72 h. The diminution of the substitutional disorder is essential in these types of compounds, as the half-metallic character and the magnetic properties are primarily influenced by this factor.

Keywords
Heusler compounds, Substitutional disorder, X-ray diffraction, Neutron diffraction

Published online 11/5/2018, 9 pages
Copyright © 2018 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: Radu GAVREA, Marin COLDEA, Lucian BARBU-TUDORAN, Olivier ISNARD, Viorel POP. Diana BENEA, ‘Reduction of the substitutional disorder by heat treatments in Mn2-xCoxVAl Heusler alloys’, Materials Research Proceedings, Vol. 8, pp 219-227, 2018

DOI: http://dx.doi.org/10.21741/9781945291999-25

The article was published as article 25 of the book Powder Metallurgy and Advanced Materials

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

References
[1] M. Meinert, J. M. Schmalhorst, G. Reiss, E. Arenholz, Ferrimagnetism and disorder of epitaxial Mn2−xCoxVAl Heusler compound thin films, J. Phys. D: Appl. Phys. 44 (2011) 215003. https://doi.org/10.1088/0022-3727/44/21/215003
[2] I. Galanakis, K. Ozdogan, E. Sasioglu, B. Aktas, Doping of Mn2VAl and Mn2VSi Heusler alloys as a route to half-metallic antiferromagnetism, Phys. Rev. B 75 (2007) 092407. https://doi.org/10.1103/PhysRevB.75.092407
[3] C. Felser, A. Hirohata, Heusler alloys – Properties Growth and Applications, Springer Series in Materials Science, Springer International Publishing, Switzerland, 2016.
[4] B. Deka, A. Srinivasan, R. K. Singh, B. S. D. C. S. Varaprasad, Y. K. Takahashi, K. Hono, Effect of Co substitution for Mn on spin polarization and magnetic properties of ferrimagnetic Mn2VAl, J. Alloys Compd. 662 (2015) 510-515. https://doi.org/10.1016/j.jallcom.2015.12.089
[5] Y. Yoshida, M. Kawakami, T. Nakamichi, Magnetic Properties of a Ternary Alloy Mn0.5V0.5-yAly, J. Phys. Soc. Japan 50 (1981) 2203-2208. https://doi.org/10.1143/JPSJ.50.2203
[6] R. Gavrea, A. Bolinger, V.Pop, O. Isnard, M.Coldea, D. Benea, Phys. Status Solidi B (2017).
[7] R. Gavrea, C. Leostean, M. Coldea, O Isnard, V. Pop and D. Benea, Effects of Co for Mn substitution on the electronic properties of Mn2-xCoxVAl as probed by XPS, Intermetallics, 93 (2018) 155-161. https://doi.org/10.1016/j.intermet.2017.12.003
[8] Y. Takamura, R. Nakane, S. Sugahara, Analysis of L21-ordering in full-Heusler Co2FeSi alloy thin films formed by rapid thermal annealing, J. Appl. Physics 105 (2009) 07B109.
[9] ILL yellow book, available at www.ill.fr.
[10] J. Rodriguez-Carvajal, Recent advances in magnetic structure determination by neutron powder diffraction, Physica B, 192 (1993) 55-69. https://doi.org/10.1016/0921-4526(93)90108-I
[11] C. Jiang, M. Venkatesan, J. M. D. Coey, Transport and magnetic properties of Mn2VAl: Search for half-metallicity, Solid State Comm. 118 (2001) 513-516. https://doi.org/10.1016/S0038-1098(01)00151-X
[12] T. Nakamichi, C.V. Stager, Phenomenological formula of NMR satellite of Heusler alloys and magnetic structure of Mn2VAl, J. Magn. Magn. Materials 31(1983) 85. https://doi.org/10.1016/0304-8853(83)90165-8
[13] K. R. A. Ziebeck and P. J. Webster, A neutron diffraction and magnetization study of Heusler alloys containing Co and Zr, Hf, V or Nb, J. Phys. Chem. Solids 35 (1974) 1-7. https://doi.org/10.1016/0022-3697(74)90002-X