A new mechanism for temperature sensing based on the thermal population of 7F2 state in Eu3+

The thermal coupling property of the ground state F-7(0) and its adjacent thermally-excited state 7F2 of Eu3' ion was firstly discussed and a new temperature sensing mechanism was proposed based on the thermal population of F-7(2) state in Y2O3 : 5% Eu3+ powder sample. Under a constant 611.2 nm excitation, the fluorescence originating from 5D0 state increases monotonously as the temperature rises in the region from 150 K to 300 K. The reason leading to this temperature-dependent fluorescence behavior was analyzed in detail. It is demonstrated that this present work provides a new mechanism for non-contact optical thermometry. (C) 2016 Elsevier B.V. All rights reserved.