中国物理B ›› 1997, Vol. 6 ›› Issue (9): 697-711.doi: 10.1088/1004-423X/6/9/008

• • 上一篇    

ELECTRONIC STRUCTURE AND CRYSTALLINE ELECTRIC FIELD IN Rco5(R= Y, La, Ce, Pr, Nd, Sm, Gd, and Tb)

曾雉1, 郑庆祺1, 王学凤2, 金汉民2, 孙家钟2, 韩秀峰3, 杨伏明3   

  1. (1)Institute of Solid State Physics,Academia Sinica, Hefei 230031,China; (2)Jilin University, Changchun 130023, China; (3)State Key Laboratory of Magnetism,Institute of Physics,Academia Sinica,Beijing 100080, China
  • 收稿日期:1996-11-14 出版日期:1997-09-20 发布日期:1997-09-20
  • 基金资助:
    Project supported in part by the National Natural Science Foundation of China.

ELECTRONIC STRUCTURE AND CRYSTALLINE ELECTRIC FIELD IN Rco5(R= Y, La, Ce, Pr, Nd, Sm, Gd, and Tb)

HAN XIU-FENG (韩秀峰)a, YANG FU-MING (杨伏明)a, ZENG ZHI (曾雉)b, ZHENG QING-QI (郑庆祺)b, WANG XUE-FENG (王学凤)c, JIN HAN-MIN (金汉民)c, SUN JIA-ZHONG (孙家钟)c   

  1. a State Key Laboratory of Magnetism,Institute of Physics,Academia Sinica,Beijing 100080, China;
    b Institute of Solid State Physics,Academia Sinica, Hefei 230031,China; 
    c Jilin University, Changchun 130023, China
  • Received:1996-11-14 Online:1997-09-20 Published:1997-09-20
  • Supported by:
    Project supported in part by the National Natural Science Foundation of China.

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摘要： Self consistent charge and spin polarized local spin-density approximation functional theory calculations based on the discrete variational method have been performed for RCo5(R=Y, La, Ce, Pr, Nd, Sm, Gd, and Tb) compounds. The partial density of states of the Pr atom in the PrCo6Co12 cluster is established to be strikingly similar to that of the Ce atom in the CeCo6Co12 cluster, supporting the suggestion that the Pr atom is valence fluctuating. The radii ＜r4f＞ and ＜r4f2＞ of the 4f electrons of the R atom from La to Tb, except Ce, show the lanthanide contraction. The crystalline electric field (CEF) parameter A02 at the R site is calculated using a real charge distribution ρ(R) in the cluster, except for Pr and Nd, and is in agreement with that evalu ated based on the single-ion model. This result shows that the CEF parameter A02 is mainly determined by the near electronic structure. There exists a hybridization in a certain degree between the light rare-earth R-4f and Co-3d orbitals in some single-electron-molecular-orbitals, which are n ear the Fermi energy level and occupied by electrons. For light rare-earths the R-4f electrons in R Co6Co12(R=Y, La, Ce, Pr, Nd, and Sm) clu sters are not localized entirely and a small amount of the R-4f electrons have itinerant properties.

Abstract: Self consistent charge and spin polarized local spin-density approximation functional theory calculations based on the discrete variational method have been performed for RCo5(R=Y, La, Ce, Pr, Nd, Sm, Gd, and Tb) compounds. The partial density of states of the Pr atom in the PrCo6Co12 cluster is established to be strikingly similar to that of the Ce atom in the CeCo6Co12 cluster, supporting the suggestion that the Pr atom is valence fluctuating. The radii ＜r4f＞ and ＜r4f2＞ of the 4f electrons of the R atom from La to Tb, except Ce, show the lanthanide contraction. The crystalline electric field (CEF) parameter A02 at the R site is calculated using a real charge distribution $\rho$(R) in the cluster, except for Pr and Nd, and is in agreement with that evalu ated based on the single-ion model. This result shows that the CEF parameter A02 is mainly determined by the near electronic structure. There exists a hybridization in a certain degree between the light rare-earth R-4f and Co-3d orbitals in some single-electron-molecular-orbitals, which are n ear the Fermi energy level and occupied by electrons. For light rare-earths the R-4f electrons in R Co6Co12(R=Y, La, Ce, Pr, Nd, and Sm) clu sters are not localized entirely and a small amount of the R-4f electrons have itinerant properties.

中图分类号:  (Rare earth metals and alloys)

  • 71.20.Eh
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 71.20.Be (Transition metals and alloys)