ESCA investigations of amorphous and crystalline zirconium acid phosphates

Amorphous and micro-crystalline α- and γ-zirconium acid phosphates have been investigated by the ESCA technique. α-zirconium phosphate has been also studied as a single crystal. Both the B.E. of zirconium and phosphorous electrons in zirconium phosphates are slightly higher than those reported for zirconium derivatives and trivalent metal phosphates, indicating a stronger polarization of the ZrO and PO bonds. Furthermore, it seems that some ESCA features of the zirconium phosphates investigated are structure dependent. However, no definitive conclusions have been drawn because of the lack of knowledge of the "charging-up" phenomena in protonic conductors such as zirconium phosphates. Satellite structures have been observed in the P2s, P2p, Zr3d and Zr4p regions. The position and the intensity of these "shake-up" effects are again dependent on the nature of the examined phase and they seem to be due to the presence of electron defect structures induced by X-rays or already present in the original samples.