High-Pressure Eu3+ → Eu2+ Reduction in a Matrix with the Structure of Apatite Silicate

Phosphor Ca2La6.8Eu1.2(SiO4)6O2−δ is obtained via coprecipitation and the nitrate-citrate pyrolysis method. The structure and phase composition of the synthesized apatite silicates are studied using XRD. The luminescence spectra of the sample are registered before and after pressing at pressures above 5 GPa. The magnetic properties are analyzed by means of ESR spectroscopy and vibration magnetometry. The concentrations of Eu2+ ions and constants (λ) of optical splitting between 7FJ levels in the initial sample, and in the sample after hot pressing, are calculated.