Thermal dehydration of SrHPO4 α- and β-forms

Using DTA, TT, DTB, X-ray phase analysis, infrared spectroscopy, and electrical conductivity methods, the process of thermal dehydration of α- and β-modifications of SrHPO4 has been investigated. The following has been established: both under the atmospheric pressure and in vacuum, the dehydration of α- SrHPO4 and β - SrHPO4 proceeds in different ways: α - SrHPO4 is dehydrated in one step within the temperature range of 340 deg to 420 deg C, while the evolution of water from β- SrHPO4 occurs in one step within the temperature range of 340 deg to 600 deg C with the formation of an intermediate crystalline phase of variable composition Sr2P2O7. xnSrHPO4. The end product of dehydration of α- and β-modifications of SrHPO4 is β-Sr2P2O7, which is converted into α - form at the temperature above 750 deg C