X-ray spectroscopy investigation of hydrogen-containing phases based on the compounds of tungsten with VI group elements

New data on both electronic and atomic structures of hydrogen bronze, HxWO3, and a compound HxWSe2 with a layered structure have been obtained using two methods of X-ray absorption spectroscopy — XANES and EXAFS. Information about interatomic interaction, metal–hydrogen bonds and their ionic component has been obtained by means of an investigation of positions and shapes of the LIII-absorption edge of tungsten and K-absorption edge of selenium in the nearest absorption region (XANES) in WSe2, WO3 and HxWSe2, HxWO3. A possibility of investigation of changes in the atomic-crystalline structure during transformation WO3⇒HxWO3 and WSe2⇒HxWSe2 was tested, studying changes of the extended fine structure (EXAFS) of the X-ray LIII-absorption spectra of tungsten and K-absorption spectra of selenium. The analysis of spectra fine structure indicates a sensibility of the EXAFS-method concerning small atom displacements in the WO3 and WSe2 compounds due to hydrogen insertion.