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Valence Fluctuations in CeCo2 and Ti-Doped CeCo2

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Abstract

We report on the magnetic measurements of polycrystalline samples of CeCo2 and CeCo(2−x)Ti x (x = 0.01, 0.02, 0.03, 0.04, and 0.05) which have been synthesized by an arc melting technique. All these compounds crystallize into the face-centered cubic (FCC) structure with the Fd\( \bar{3} \)m space group. The lattice parameter decreases linearly with increasing Ti content from 7.15808(5) Å for x = 0 (CeCo2) to 7.15231(7) Å for x = 0.05. The magnetic behavior of these compounds has been investigated in the temperature range 5–400 K. The zero field-cooled (ZFC) and field-cooled magnetization (FC) curves show irreversibility below T = 400 K. This result indicates that an inhomogeneous, dynamic magnetic state exists over a wide temperature range. The magnetic susceptibility for both ZFC and FC cases initially decreases with Ti content and then increases with further Ti addition. This behavior is interpreted in terms of band magnetism in the presence of magnetic clusters. This result indicates that the magnetic inhomogeneity of these alloys becomes dominant over a wide temperature range. The observed temperature dependence of the magnetic susceptibility leads us to suggest that these compounds are in a mixed-valence state of the magnetic Ce3+ ions and non-magnetic Ce4+ ions. This fact allows us to successfully interpret the ZFC magnetic susceptibility data with the two-level ionic inter-configuration fluctuations model. We also observe that the magnetic susceptibility increases by the addition of Ti, as evidenced by the enhancement of the formation of magnetic Co clusters due to local disorder. Finally, the magnetic state below the Curie temperatures are discussed based on Griffiths-like behavior.

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References

  1. J. Park, M. Ellerby, K.A. McEwen, and M. de Podesta, J. Magn. Magn. Mater. 140–144, 2057 (1995).

    Article  Google Scholar 

  2. T.F. Smith, H.L. Luo, M.B. Maple, and I.R. Harris, J. Phys. F 1, 896 (1971).

    Article  Google Scholar 

  3. Y. Aoki, T. Nishigaki, H. Sugawara, and H. Sato, Phys. Rev. B 55, 2768 (1997).

    Article  Google Scholar 

  4. T.M. Seixas and J.M. Machado da Silva, Phys. B 269, 362 (1999).

    Article  Google Scholar 

  5. A.S. Panfilov, G.E. Grechnev, I.V. Svechkarev, H. Sugawara, H. Sato, and O. Eriksson, Phys. B 319, 268 (2002).

    Article  Google Scholar 

  6. J.M. Da, C.B. Oliveira, and I.R. Harris, J. Mater. Sci. 18, 3649 (1983).

    Article  Google Scholar 

  7. J. Fikacek, J. Prokleska, J. Prchal, J. Custers, and V. Sechovsk´, J. Phys. Condens. Matter 25, 416006 (2013).

    Article  Google Scholar 

  8. A. Fujimori, T. Miyahara, T. Koide, T. Shidara, H. Kato, H. Fukutani, and S. Sato, Phys. Rev. B 38, 7789 (1988).

    Article  Google Scholar 

  9. C.M. Varma, Rev. Mod. Phys. 48, 219 (1976).

    Article  Google Scholar 

  10. C. Tien, L.Y. Jang, C.Y. Kuo, J.J. Lu, and S.W. Feng, J. Phys. Condens. Matter 12, 8983 (2000).

    Article  Google Scholar 

  11. D. Kaczorowski, P. Rogl, and K. Hiebl, Phys. Rev. B 54, 9891 (1996).

    Article  Google Scholar 

  12. P. Swatek, D. Kacszorowski, and J. Phys, Condens. Matter 25, 055602 (2013).

    Article  Google Scholar 

  13. T.F. Smithis, H.L. Luo, M.B. Maple, and I.R. Harris, J. Phys. F Met. Phys. 1, 896 (1971).

    Article  Google Scholar 

  14. C.R. Wang, Y.Y. Chena, Y.D. Yao, C.L. Chang, Y.S. Wengb, and C.Y. Wang, J. Magn. Magn. Mater. 239, 524 (2002).

    Article  Google Scholar 

  15. A. Mauger, V.P. Boncour, M. Escorne, A.P. Guegan, J.C. Achard, and J. Darriet, Phys. Rev B 41, 2307 (1990).

    Article  Google Scholar 

  16. B.C. Sales and D.K. Wohlleben, Phys. Rev. Lett. 35, 1240 (1975).

    Article  Google Scholar 

  17. F. Tournus and A. Tamion, J. Magn. Magn. Mater. 323, 1118 (2011).

    Article  Google Scholar 

  18. Y. Oner, O. Kamer, J.H. Ross Jr, C.S. Lue, and Y.K. Kuo, Solid State Commun. 136, 533 (2005).

    Article  Google Scholar 

  19. B. Cornut and B. Coqblin, Phys. Rev B 11, 4541 (1972).

    Article  Google Scholar 

  20. C.-L. Dong, C.-L. Chen, K. Arokan, C.-L. Chang, Y.-Y. Chan, and J.-F. Lee, Lang. 25, 7568 (2009).

    Article  Google Scholar 

  21. Y. Oner and M. Guillot, J. Magn. Magn. Mater. 324, 3312 (2012).

    Article  Google Scholar 

  22. Y. Oner and M. Guillot, J. Appl. Phys. 105, 07E120 (2009).

    Article  Google Scholar 

  23. Y. Oner and O. Kamer, J. Alloys Compd. 460, 51 (2008).

    Article  Google Scholar 

  24. T. Akilan, N. Srinivasan, and R. Saravanan, Mater. Sci. Semicond. Process. 30, 381 (2015).

    Article  Google Scholar 

  25. Y. Oner and A. Guler, J. Appl. Phys. 113, 17E141 (2013).

    Article  Google Scholar 

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Acknowledgements

We thank Prof. Yayoi Takamura (University of California, Davis) for critical reading of the manuscript and useful discussions. The technical assistance of Murat Sertkol is appreciated.

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Authors and Affiliations

  1. Department of Physics Engineering, Faculty of Science and Letters, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey

    Yıldırhan Öner

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  1. Yıldırhan Öner
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Correspondence to Yıldırhan Öner.

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Öner, Y. Valence Fluctuations in CeCo2 and Ti-Doped CeCo2 . J. Electron. Mater. 46, 2211–2220 (2017). https://doi.org/10.1007/s11664-016-5160-7

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