Highly sensitive temperature reading from intensity ratio of Eu3+ And Mn4+emissions in Y3Al5O12 nanocrystals

Abstract

Potential of Eu3+, Mn4+ co-doped YAG for dual-activated luminescence intensity ratio thermometry is investigated. The samples were prepared by modified Pechini method and cubic structure confirmed by X-ray diffraction with average crystallite size of ∼ 20 nm. Scanning electron microscopy revealed different sized chunks composed of ellipsoidal-shaped particles bellow 50 nm. Temperature-dependent photoluminescent emission spectra (λex = 465 nm, 98–473 K temperature range) of co-doped samples consist of emission bands in the red spectral region originating from both Eu3+and Mn4+transitions. Concentration of Mn4+ and Eu3+ is optimized to be 0.5mol% and 3mol%. Observed suppression of Eu3+ emission indicate an efficient (∼97%) energy transfer from Eu3+ to Mn4+. Using luminescence intensity ratio as the ratio between the integrated intensities of the Eu3+ 5D0→7F1 transition and the Mn4+ 2E→4A2 manyfold, maximal absolute and relative sensitivities of SAmax = 19.2mK−1 at 351 K and SRmax = 5.06%K − 1 at 321 K were calculated.