Electronic structure and magnetic properties of CePdSb andCe1−xLaxPdSb

Abstract

Using the various full-potential linear augmented plane wave (LAPW) methods we have studied the band structure of CePdSb and ${\mathrm{Ce}}_{1\ensuremath{-}x}{\mathrm{La}}_{x}\mathrm{Pd}\mathrm{Sb}$ series of compounds. In the band calculations, CePdSb is half-metallic, i.e., metallic for majority spin while semiconducting for minority spin bands. The spin-polarized linearized muffin-tin orbital method also shows a half-metallic behavior of the ${\mathrm{Ce}}_{1\ensuremath{-}x}{\mathrm{La}}_{x}\mathrm{Pd}\mathrm{Sb}$ compounds. The magnetic investigations and the electrical resistivity data indicate the existence of a ferromagnetic state in ${\mathrm{Ce}}_{1\ensuremath{-}x}{\mathrm{La}}_{x}\mathrm{Pd}\mathrm{Sb}$ for $x\ensuremath{\leqslant}0.7$. The sample ${\mathrm{Ce}}_{0.1}{\mathrm{La}}_{0.9}\mathrm{Pd}\mathrm{Sb}$ is nonmagnetic and shows the power-law exponents in its susceptibility $\ensuremath{\Delta}\ensuremath{\chi}$, resistivity $\ensuremath{\Delta}\ensuremath{\rho}$, and specific heat $\ensuremath{\Delta}C∕T$ temperature dependences indicative of the non-Fermi liquid behavior. The $3d$ x-ray photoemission spectroscopy (XPS) spectra indicate the occupation number of the $f$-shell, ${n}_{f}=1$, in CePdSb and ${\mathrm{Ce}}_{1\ensuremath{-}x}{\mathrm{La}}_{x}\mathrm{Pd}\mathrm{Sb}$ compounds. Analysis of the $3{d}^{9}{f}^{2}$ weight in the $3d$ XPS spectra using Gunnarsson\char21{}Sch\onhammer theory suggests the $f$-states and conduction electron-states hybridization interaction $\ensuremath{\Delta}$ of about $80\phantom{\rule{0.3em}{0ex}}\mathrm{meV}$ for different configurations $x$ of the system. We interpret the XPS data in terms of the band-structure calculations.