Measurements of both the average crystal structure from Rietveld refinement of neutron powder diffraction (NPD) data and the local structure from La$L_{\rm III}$-edge x-ray-absorption fine-structure (XAFS) are presented for a La$^{11}$B$_6$ sample as a function of temperature ($\sim$10-320 K). These data are compared to XAFS results on a EuB$_6$ sample. The single-site La and B positional distribution widths and the La-B and La-La bond length distribution widths and their temperature dependence are compared. This comparison allows an estimate of the La and B site displacements, and we find that these sublattices are only slightly correlated with each other. Moreover, while the temperature dependence of the displacement parameters of the average sites from diffraction fit an Einstein model well, the temperature dependence of the La-B bond length distribution width requires at least two vibrational frequencies, corresponding to the La and B frequencies of the individual sites. XAFS data on EuB$_6$ indicate that the situation is the same in the Eu compound. In addition, comparisons between data taken below and above the ferromagnetic transition temperature for EuB$_6$ place stringent limits on the lattice involvement in the associated metal-insulator transition and the ensuing large magnetoresistance effect. This lack of lattice involvement in the magnetoresistance transition is in sharp contrast to the strong lattice involvement observed in the colossal magnetoresistance lanthanum manganese perovskites.

Temperature dependent extended x-ray absorption fine structure (EXAFS)spectra were measured for a 3.3 at\% Ga stabilized Pu alloy over the range $T$= 20 - 300 K. EXAFS data were acquired at both the Ga $K$-edge and the Pu$L_{\textrm{III}}$-edge. Curve-fits were performed to the first shell interactions to obtain pair-distance distribution widths, $\sigma$, as a function of temperature. The temperature dependence of $\sigma(T)$ was accurately modeled using a correlated-Debyemodel for the lattice vibrational properties, suggesting Debye-like behavior in this material. Using this formalism, we obtain pair-specific correlated-Debye temperatures, $\Theta_{\textrm{cD}}$, of 110.7$\pm$1.7 K and 202.6 $\pm$3.7 K, for the Pu-Pu and Ga-Pu pairs, respectively. The result for the Pu-$\Theta_{\textrm{cD}}$ value compares well with previous vibrational studies on $\delta$-Pu. In addition, our results represent the first unambiguous determination of Ga-specific vibrational properties in Pu-Ga alloys, i.e, $\Theta_{\textrm{cD}}$ for the Ga-Pu pair. Because the Debye temperature can be related to a measure of the lattice stiffness, these results indicate the Ga-Pu bonds are significantly stronger than the Pu-Pu bonds. This effect has important implications for lattice stabilization mechanisms in these alloys.

The magnetic and electronic properties of non-Fermi liquid UCu_4Pd depend on annealing conditions. Local structural changes due to this annealing are reported from UL_III- and Pd K-edge x-ray absorption fine-structure measurements. In particular, annealing decreases the fraction of Pd atoms on nominally Cu 16$e$ sites and the U-Cu pair-distance distribution width. This study provides quantitative information on the amount of disorder in UCu_4Pd and allows an assessment of its possible importance to the observed non-Fermi liquid behavior.