Fermi surface and magnetic properties ofCexLa1−xSballoys(x=0.5,0.9)

Abstract

We have investigated the Fermi surface (FS) and magnetic properties of ${\mathrm{Ce}}_{x}{\mathrm{La}}_{1\ensuremath{-}x}\mathrm{Sb}$ alloys for $x=0.9,0.5$ by means of the de Haas--van Alphen effect and high-field magnetization measurements. We successfully observed quantum oscillations in ${\mathrm{Ce}}_{0.5}{\mathrm{La}}_{0.5}\mathrm{Sb}$ and determined its Fermi surface. The other missing \ensuremath{\alpha} FS due to the p-f mixing effect in ${\mathrm{Ce}}_{x}{\mathrm{La}}_{1\ensuremath{-}x}\mathrm{Sb}$ at high concentration, which degenerates for spins in LaSb at the ${X}_{z}$ point, was found in ${\mathrm{Ce}}_{0.5}{\mathrm{La}}_{0.5}\mathrm{Sb}.$ The obtained results indicate that the FS and magnetic properties of ${\mathrm{Ce}}_{x}{\mathrm{La}}_{1\ensuremath{-}x}\mathrm{Sb}$ exhibit a remarkable transformation, strongly dependent on La substitution due to the suppression of the p-f mixing effect. These results indicate that the p-f mixing effect becomes weaker and, consequently, the crystalline electric field effect becomes dominant in ${\mathrm{Ce}}_{x}{\mathrm{La}}_{1\ensuremath{-}x}\mathrm{Sb}$ with increasing La concentration.