High Pressure optical nanothermometer based on Er3+ photoluminescence

The optical properties of a sparsely investigated material, LaGdO3 doped with Er3+, are explored regarding its suitability as nanothermometer. Besides its excellent capabilities for dielectric applications, when doping with Er3+, this material provides a highly efficient up-conversion photoluminescence (PL) for high temperature thermometry at high pressure due to its structural stability. LaGdO3 belongs to the perovskite-type ABO3 compounds with a B-type monoclinic C2/m space group (a = 14.43 Å; b = 3.69 Å; c = 9.00 Å; and β = 100.70º) at ambient conditions. It undergoes a structural phase transition to a hexagonal P3¯m1 phase at 3 GPa yielding a notable PL enhancement, thus enabling it as a potential high-pressure high-temperature nanothermometer.