立方萤石结构CeO2Cl0.07的高压复分解反应合成与物性表征OA

The 4f electron of Ce has long attracted extensive attention due to their unique delocalization mechanism and their influence on atomic structure,phase transformation behavior,and magnetic structure.In this paper,CeO2Cl0.07 was synthesized with a cubic fluorite structure by changing the stoichiometry of the precursors(CeCl3,MgO powder)and regulating the high-pressure solid-state metathesis(HSM)reaction under high temperature and high pressure conditions(1 873 K,5 GPa)provided by a large volume press.Then pressure was provided by a diamond anvil cell(DAC),and the sample was characterized by high-pressure in-situ synchrotron X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and high-pressure Raman spectroscopy.By comparing the obtained pressure-volume(p-V)curve with CeO2,it is found that CeO2Cl0.07 is more compressible.The high-pressure Raman phonon spectrum(F2g)is obtained,indicating that the pressure-dependent behavior of CeO2Cl0.07 exhibits anomalous changes at 0-2 GPa and near 15 GPa under non-hydrostatic pressure.We believe that the doping of Cl elements introduces oxygen vacancies,which increases the concentration of Ce3+,thereby causing the delocalization of 4f electron and resulting in the observed phenomenon.This study developed a new high-pressure synthesis pathway for cerium-based compounds and revealed their behavior under high-pressure conditions.