PECULIAR OPTICAL PROPERTIES OF Co2MnGa ALLOYS
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Keywords

Ellipsometry
magneto-optical Kerr effect
semi-Heusler alloy

Abstract

Co2MnGa alloy was prepared by the conventional arc-melting method. The optical conductivity (OC) spectrum of the alloy was measured by a rotating-analyzer spectroscopic ellipsometer. The OC spectrum was also calculated based on the electronic structure by using the full-potential linearized-augmented-plane-wave method within the local-spin-density approximation to the density-functional theory. The calculated OC spectrum does not agree well with the experimental one. Since the Co2MnGa alloy could be a strongly-correlated material, the so-called 'LDA+U' method was applied with U = 5.4 eV. The calculated OC spectrum using the 'LDA+U' method agrees very well with the experimental one. The inclusion of the onsite Coulomb
potential during the self-consistent calculation significantly modifies the minorityspin Co and Mn 3d bands, resulting in a contraction of the energy gaps between states which are strongly involved in interband absorption peaks.

https://doi.org/10.29037/ajstd.181
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References

van Engen, P.G., Buschow, K.H.J., Jongebreur, R., and Erman, M. (1983), Appl. Phys. Lett., vol. 42, p. 202.

van der Heide, P.A.M., Baelde, W., de Groot, R.A., de Vroomen, A.R., van Engen, P.G., and Buschow, K.H.J. (1985), J. Phys.F: Met. Phys., vol. 15, p. L75.

Ohyama, R., Koyanagi, T., and Matsubara, K. (1987), J. Appl. Phys., vol. 61, p. 2347.

Kubo, Y., Takakura, N., and Ishida, S. (1983), J. Phys. F: Met. Phys., vol. 13, p. 161.

Ishida, S., Akazawa, S., Kubo, Y., and Ishida, J. (1982), J. Phys. F: Met. Phys., vol. 12, p. 1111.

Kubo, Y., Ishida, S., and Ishida, J. (1981), J. Phys. F: Met. Phys., vol. 11, p. 2443.

Shreder, E.I., Kirillova, M.M., and Dyakina, V.P. (1996), Phys. Met. Metalogr., vol. 81, p. 406.

Kirillova, M.M., Kuz'min, Yu.I., Knyazev, Yu.V., and Shreder, E.I. (1997), Phys. Met. Metalogr., vol. 83, p. 590.

van Ek, J., Huang, W., and MacLaren, J.M. (1997), J. Appl. Phys., vol. 81, p. 5429.

Shreder, E.I., Kirillova, M.M., and Dyakina, V.P. (2000), Phys. Met. Metalogr., vol. 90, p. 362.

Martynov, V.V. and Kokorin, V.V. (1992), J. Phys., vol. III 2, p. 739.

Ullakko, K., Huang, J.K., Kantner, C., and O'Handley, R.C. (1996), Appl. Phys. Lett., vol. 69.

Hu, F.X., Shen, B.G., Sun, J.R., and Wu, G.H. (2001), Phys. Rev., vol. B 64, p. 132412.

Kudryavtsev, Y.V., Lee, Y.P., and Rhee, J.Y. (2002), Phys. Rev., vol. B 66, p. 115114.

Zhou, Y., Jin, X., Xu, H., Kudryavtsev, Y.V., Lee, Y.P., and Rhee, J.Y. (2002), J. Appl. Phys., vol. 91, p. 9894.

Rhee, J.Y., Kudryavtsev, Y.V., Dubowik, J., and Lee, Y.P. (2003), J. Appl. Phys., vol. 91, p. 5527.

Anisimov, V.I., Solovyev, I.V., Korotin, M.A., Czyzyk, M.T., and Sawatzky, G.A. (1993), Phys. Rev., vol. B 48, p. 16929.

Anisimov, V.I., Zaanen, J., and Andersen, O.K. (1991), Phys. Rev., vol. B44, p. 943

Czyzyk, M.T. and Sawatzky, G.A. (1994), Phys. Rev., vol. B 49, p. 14211.

Blaha, P., Schwarz, K., Madsen, G.K.H., Kvasnicka, D., and Luitz, J. (2001), WIEN2k, An Augmented Plane Wave + Local Orbitals Program for Calculating Crystal Properties (Karl-heinz Schwarz, Techn. Universitat Wien, Wien, Austria).

Wimmer, E., Krakauer, H., Weinert, M., and Freeman, A.J. (1981),

Phys. Rev., vol. B 24, p. 864.

Perdew, J.P., Burke, K., and Ernzerhof, M. (1996), Phys. Rev. Lett., vol. 77, p. 3865.

Rhee, J.Y. (2003), J. Korean Phys. Soc., vol. 43, p. 792.

J. Korean Phys. Soc., vol. 34, p. 191, (1999).

Rhee, J.Y., Kudryavtsev, Y.V., Lee, Y.P., and Kim,K.W. (2000), J. Korean Phys. Soc., vol. 36, p. 404.

Rhee, J.Y., Harmon, B.N., and Lynch, D.W. (1997), Phys. Rev., vol. B 55, p. 4124.

Kudryavtsev, Y.V., Lee, Y.P., and Rhee, J.Y. (2004), Phys. Rev., vol. B 69, p. 195104.

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