On how the mechanochemical and co-precipitation synthesis method changes the sensitivity and operating range of the BaMgEuWO optical thermometer.

The suitability of BaMgWO (BMW) double perovskite doped with Eu for the construction of an optical thermometer was tested. It has been shown that by controlling the conditions of BMW synthesis, the sensitivity of the optical thermometer and the useful range of its work can be changed. Pure BMW and doped with Eu samples were prepared using the mechano-chemical and co-precipitation methods. Both the absolute sensitivity and the relative sensitivity in relation to the synthesis route were estimated. The findings proved that the relative sensitivity can be modulated from 1.17%K at 248 K, to 1.5%K at 120 K for the co-precipitation and the mechanochemical samples, respectively. These spectacular results confirm the applicability of the BaMgWO: Eu for the novel luminescent sensors in high-precision temperature detection devices. The density-functional theory was applied to elucidate the origin of the host emission.