Electron spin resonance ofGdxLa1−xPd3intermetallic compounds

Abstract

We have extended our ESR study of Gd in the intermetallic compound ${\mathrm{Gd}}_{x}{\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Pd}}_{3}$ to samples annealed at 940\ifmmode^\circ\else\textdegree\fi{}C and cooled rapidly to room temperature. We have measured the ESR linewidths and $g$ shifts as a function of temperature and concentration of Gd. They were found to exhibit Korringa-like thermal broadening between 6 and 40\ifmmode^\circ\else\textdegree\fi{}K. We have deduced the average value of ${J}_{\mathrm{eff}}$ for the effective-exchange integral to be 0.24 \ifmmode\pm\else\textpm\fi{} 0.03 eV. We have calculated also the magnitudes of the conduction-electron relaxation rates to the lattice, (i) due to the undisturbed host lattice, (ii) by spin-flip scattering due to the magnetic impurity Gd, and (iii) by spin-flip scattering due to the nonmagnetic impurity Th.