Temperature dependencies of Ni, Cu and Mo metals EXAFS spectra were studied in order to determine the anharmonic pair potential. The potential parameters for metals with cubic structure-Ni, Cu, Mo as well as for Pb (Stern E A et al 1991 Phys. Rev. B 43 8850), Au, Ag (Newville M and Stern E A http://krazy.phys.washington.edu/paper/ag-au.html)-obtained earlier, were analysed to find correlations with other physical characteristics. It was found that a, b potential parameter values correlate with cohesive energy and interatomic distance for face-centred-cubic structure metals. Obtained potential parameter values were used to determine thermodynamics parameters, including the linear coefficient of thermal expansion, the Debye temperature, the bulk modulus and the Grunesien parameter.

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The temperature-dependent Nb K-edge absorption spectra of several mixedion Pb-containing perovskite compounds were analysed to determine the Nb displacement and to trace its changes through the phase transitions. Both extended x-ray absorption fine structure (EXAFS) and the pre-edge region of the spectra were involved in the analysis. The results show that, in the compounds studied, Nb occupies an off-centre position with symmetry lower than that implied by macroscopic symmetry. The magnitude and direction of the Nb off-centre displacement do not display any noticeable temperature change and are not affected by the change in macroscopic symmetry. The Nb-O distribution and its temperature evolution do not show any distinct dependence on the degree of compositional ordering and properties of the samples.

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