X-ray absorption spectroscopy of PbMoO₄ single crystals

Abstract

X-ray absorption spectra of PbMoO₄ (LMO) crystals have been investigated for the first time in literature. The measurements have been carried out at Mo absorption edge at the dispersive EXAFS beamline (BL-8) of INDUS-2 Synchrotron facility at Indore, India. The optics of the beamline was set to obtain a band of 2000 eV at 20,000 eV and the channels of the CCD detector were calibrated by recording the absorption edges of standard Mo and Nb foils in the same setting. The absorption spectra have been measured for three LMO samples prepared under different conditions viz. (i) grown in air from stoichiometric starting charge, (ii) grown in argon from stoichiometric starting charge and (iii) grown in air from PbO-rich starting charge. The results have been explained on the basis of the defect structure analysed in LMO crystals prepared under different conditions. The Mo absorption edge is significantly influenced by the deviations in crystal stoichiometry.