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http://dx.doi.org/10.3740/MRSK.2019.29.7.451

The Magnetic and Thermal Properties of a Heavy Fermion CeNi2Ge2  

Jeong, Tae Seong (Hanshin University)
Publication Information
Korean Journal of Materials Research / v.29, no.7, 2019 , pp. 451-455 More about this Journal
Abstract
The electromagnetic and thermal properties of a heavy fermion $CeNi_2Ge_2$ are investigated using first-principle methods with local density approximation (LDA) and fully relativistic approaches. The Ce f-bands are located near the Fermi energy $E_F$ and hybridized with the Ni-3d states. This hybridization plays important roles in the characteristics of this material. The fully relativistic approach shows that the 4f states split into $4f_{7/2}$ and $4f_{5/2}$ states due to spin-orbit coupling effects. It can be found that within the LDA calculation, the density of states near the Fermi level are mainly of Ce-derived 4f states. The Ni-derived 3d states have high peaks around -1.7eV and spreaded over wide range around the Fermi level. The calculated magnetic of $CeNi_2Ge_2$ with LDA method does not match with that of experimental result because of strong correlation interaction between electrons in f orbitals. The calculations show that the specific heat coefficient underestimates the experimental value by a factor of 19.1. The discrepancy between the band calculation and experiment for specific heat coefficient is attributed to the formation of a quasiparticle. Because of the volume contraction, the exchange interaction between the f states and the conduction electrons is large in $CeNi_2Ge_2$, which increases the quasiparticle mass. This will result in the enhancement of the specific hear coefficient.
Keywords
$CeNi_2Ge_2$; magnetic property; heavy fermion; specific heat coefficient;
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1 B. Bogenberger and H. Lohneysen, Phys. Rev. Lett., 74, 1016 (1995).   DOI
2 F. M. Grosche, S. R. Julian, N. D. Mathur and G. Glonzarich, Physica B, 50, 223 (1996).
3 I. R. Walker, F. M. Grosche, D. M. Freye and G. G. Lonzarich, Physica C, 303, 282 (1997).
4 F. Steglich, B. Buschinger, P. Gegenwart, M. Lohman, R. Helfrich, C. Laghammer, P. Hellmann, L. Donnervea, S. Thomas, A. Link, C. Geibel, M. Lang, G. Sparn and W. Assmus, J. Phys.: Condens. Matter, 8, 9909 (1996).   DOI
5 H. Kadowaki, B. Fak, T. Fukuhara, K. Maezawa, K. Nakajima, M. A. Adams, S. Raymond and J. Flouquet, Phys. Rev. B, 68, 140402 (2003).   DOI
6 G. Sparn, P. C. Canfield, P. Hellmann, M. Keller, A. Link, R. A. Fisher, N. E. Phillips, J. D. Thompson and F. Steglich, Physica B, 212, 206 (1997).
7 G. Knopp, A. Loidl, R. Caspary, U. Gottwick, C. D. Bredl, H. Spille, F. Steglich and A. P. Murari, J. Magn. Magn. Mater., 74, 341 (1997).   DOI
8 D. Ehm, F. Feinert, G. Nicolay, S. Schmidt, S. Hufner, R. Claessen, V. Eyert and C. Geibel, Phys. Rev. B, 64, 235104 (2001).   DOI
9 K. Koepernik, H. Eschrig, Phys. Rev. B 59, 1743 (1999).   DOI
10 H. Eschrig, Optimized LCAO Method and the electronic Structure of Extended Systems. p.1, Springer, Berlin (1989).
11 J. P. Perdew, Y. Wang, Phys. Rev. B, 45, 13244 (1992).   DOI
12 B. Fak, J. Flouquet, G. Lapertot, T. Fukuhara, H. Kadowaki, J. Phys.: Condens. Matter, 12, 5423 (2000).   DOI
13 Y. Aoki, J. Urakawa, H. Sugawara, H. Sato, T. Fukuhara, K. Maezawa, J. Phys. Soc. Japan, 66, 2993 (1997).   DOI