Thermometric analysis of the near-infrared emission from Er3+ in yttrium silicate powders containing Mg2+

Highlights: • Er³⁺ doped yttrium silicate powders (EDYSPs) prepared by combustion synthesis. • The influence of Mg²⁺ on the structural and optical properties of EDYSPs. • The influence of Mg²⁺ and Er³⁺ doping levels on the thermal sensitivity of EDYSPs. Here, we investigate erbium (Er³⁺) doped yttrium silicate powders prepared by combustion synthesis and the effect of magnesium (Mg²⁺) on its structural and luminescence characteristics for application in optical thermometry in the near-infrared. Surface morphology and structure of the powders were investigated by X-ray powder diffraction, scanning electronic microscopy, infrared Fourier transform and Raman spectroscopy. CW laser excitation at the visible (λ = 532 nm) produced near-infrared emission corresponding to ²H_11/2 → ⁴I_13/2 and ⁴S_3/2 → ⁴I_13/2 electronic transitions of Er³⁺. Using the luminescence intensity ratio approach, which takes into account the thermal coupling among states ²H_11/2 and ⁴S_3/2, the optical temperature sensing performance was investigated in the range 298–673 K. Maximum sensitivity of ∼0.001/K was obtained at 510 K for near-infrared emission from the sample containing 8 wt. % of Mg²⁺ and 4 wt. % of Er³⁺.