Pressure and temperature sensing properties of Nd3+:YTaO4 luminescence

The pressure- and temperature-dependent luminescence properties of M'-phase Nd3+:YTaO4 phosphor synthesized by a method of molten salt synthesis are presented. Ten near-infrared emission lines originate from the transitions between the two Stark levels R1, 2 of 3F3/2 state and the five Stark levels Z1, 2, 3, 4, 5 of 4I9/2 state for the Nd3+ ions doped can be clearly identified at ambient condition. All these emission lines are found to shift linearly with pressure in a range up to 11 GPa. The R2, 1 → Z5 emission lines are the most sensitive to pressure, and the corresponding pressure sensitivities are 16.44 and 14.27 cm−1/GPa. Intensities of all the emission lines evolve with pressure non-monotonically, and peak up at ~1 GPa. The R1 → Z4, 5 and R2 → Z1 emission lines can be obviously narrowed under the hydrostatic pressure, and broadened under the non-hydrostatic pressure, indicating their potential capability for reflecting the characteristic of pressure condition. Intensity ratio of the R2, 1 → Z5 emission lines exhibits a large temperature dependence, the corresponding relative sensitivity is between 0.125% and 0.108% K-1 in the physiological temperature range 290 – 320 K. Thermal variations of spectral positions and widths of the R2, 1 → Z5 emission lines are also investigated. A high thermal stability for the position of R2 → Z5 emission line is revealed. Based on these experimental results, the advantages and potentials of Nd3+:YTaO4 as a sensor for pressure and temperature are discussed.