Preparation, structure and temperature dependence of spectral properties of Yb3+/Er3+ doped Sr5(PO4)3F transparent glass ceramics

Highlights: • Sr₅(PO₄)₃F transparent glass ceramics (GCs) were achieved for the first time. • Structure and UC luminescence properties of Yb³⁺/Er³⁺ doped transparent GCs were studied. • Three UC emission underwent the process of absorbing two photons. • The maximum relative sensitivity of 1.26% K⁻¹ at 303 K can be achieved. • The maximum absolute sensitivity of 0.31% K⁻¹ at 526 K is obtained. -- Abstract: The Sr₅(PO₄)₃F transparent glass ceramics (GCs) were achieved for the first time by crystallizing from low-cost lead-free borate glasses. The structure, optical and Up-conversion luminescence characteristics of Yb³⁺/Er³⁺ co-doped transparent GCs were studied. The results show that the luminescence properties of Sr₅(PO₄)₃F transparent GCs are distinctly improved compared with precursor glass, which stands to benefit from both low phonon energy environment of Sr₅(PO₄)₃F GCs and the unique structural features of fluorapatite. Under the 980 nm laser, the optical temperature measurement performance of GC samples was evaluated based on the fluorescence intensity ratio by using thermal coupling energy level of Er³⁺ ion. In this wide temperature range from 303 K to 653 K, the maximum relative sensitivity and maximum absolute sensitivity obtained are 1.26% K⁻¹ and 0.31% K⁻¹, respectively. It is expected to be applied in the field of optical temperature sensing.