Photoemission spectra, hybridization, and Coulomb correlation in RT2 (R=Y,Ce,Pr,Nd,Sm,Gd; T=Fe,Co,Ni)

Abstract

The effects of the R 4f/T 3d hybridization and the Coulomb correlation in the R4f and T 3d photoemission spectra of RT2 compounds (R = Y, Ce, Pr, Nd, Sm, Gd; T = Fe, Co, Ni) have been investigated. The calculated R 4f/T 3d hybridization parameters decrease with an increasing atomic number from R = Ce to Gd for the same T, and from RCo2 to RNi2 for the same R. These trends are consistent with those in the photoemission spectra. The calculated quasi-particle spectral densities indicate the importance of the on-site Coulomb correlation of the T 3d electrons in the electronic structures of RT2.