The influence of dopant concentration and grain size on the ability for temperature sensing using nanocrystalline MgAl2O4:Co2+,Nd3+ luminescent thermometers†
In this work, for the first time, the ability of nanocrystalline MgAl2O4:Co2+ and MgAl2O4:Co2+,Nd3+ phosphors for temperature sensing was investigated in a wide temperature range. It has been proved that the emission intensity of Co2+ can be modulated either by its concentration or by the size of nanocrystals. The highest relative sensitivity was obtained for MgAl2O4:0.01% Co2+,5% Nd3+ annealed at 1100 °C (about 0.3% °C−1). The provided analysis reveals that Co2+ and Nd3+ are located in tetrahedral sites of Mg2+ ions. The presented results show that Co2+ luminescence depends on temperature changes of its environment, and it is found that nanothermometers doped with Co2+ could be a potential temperature sensors in luminescent thermometry.