Site Occupation of Eu2+ in Ba2- xSr xSiO4 ( x = 0-1.9) and Origin of Improved Luminescence Thermal Stability in the Intermediate Composition

Site Occupation of Eu2+ in Ba2- xSr xSiO4 ( x = 0-1.9) and Origin of Improved Luminescence Thermal Stability in the Intermediate Composition