Pressure-induced amorphization of zinc orthophosphate—Insight in the zinc coordination by XAS

•Use of in-situ high pressure EXAFS applied on α-Zn3(PO4)2.•Evidence of an amorphization of the α-Zn3(PO4)2 induced by the pressure.•Evidence of an irreversible zinc coordination change with the pressure.

In-situ high pressure X-ray absorption spectroscopy measurements at Zn K-edge were performed on α-Zn3(PO4)2 compound, one of the model materials of the tribochemical film obtained from the ZDDP molecule. The goal of these synchrotron experiments was to investigate pressure-induced effects on the local environment of zinc atoms during a compression/decompression cycle. Modifications of the absorption spectra at Zn K-edge of α-Zn3(PO4)2 show irreversible amorphization around zinc atoms and irreversible increase of the Zn–O distance. These results were identified as the signature of structural changes around the Zn atom in the pressed sample, thus suggesting an irreversible Zn coordination change with the pressure.