X-ray-absorption near-edge-structure study ofEuPd3Bx: A mixed-valence system

$L_3$ absorption spectra of Eu in boron-containing alloys, ${\mathrm{EuPd}}_3{\mathrm{B}}_x$ ($x=0, 0.25, 0.5, \mathrm{and} 1.0$) have been recorded. Direct evidence for the mixed-valence (${\mathrm{Eu}}^{3+}$ and ${\mathrm{Eu}}^{2+}$) behavior of Eu in Eu${\mathrm{Pd}}_3$ ${\mathrm{B}}_{0.5}$ and Eu${\mathrm{Pd}}_3$B has been provided by x-ray-absorption near-edge structure (XANES). The value of the average valence of Eu in ${\mathrm{EuPd}}_3$B and Eu${\mathrm{Pd}}_3$ ${\mathrm{B}}_{0.5}$ alloys is estimated and it is found to be temperature independent. The XANES results in conjunction with the Mössbauer measurements lead to the conclusion that Eu${\mathrm{Pd}}_3$B is an inhomogeneous mixed-valence system.