Realization of sensible peak shift thermometry from multiple site occupied Eu3+ ions in magnetically frustrated SrGd2O4.

Magnetically frustrated lattices even at low temperatures are well-known for not minimizing interaction energies. In a magnetically frustrated structure like strontium gadolinium oxide (SrGd2O4), there exists more than one suitable site for rare-earth doping due to availability of two low Gd3+ site symmetries. In the present work SrGd2O4 doped with Eu3+ ions were prepared by solid-state reaction method. Structural characterization confirms the nature of structure and bonding. Existence of different sites in the host lattice for the doped Eu3+ ions were observed via excitation spectra. Photoluminescence studies with varying temperature (15–300 K) have been extensively used with high-resolution to distinguish different sites in this structure. Studies confirm that apart of the Gd3+ sites, Sr2+ could also accommodate the Eu3+ ions. Variation of temperature that leads to shift in emission spectral peak positions has been thoroughly examined for line shift temperature sensing applicability. Low temperature uncovers emission peaks from 5D1 level that are unprovable at room temperature. Maximum relative sensitivity of 5D0 → 7F0 peak intensity to one of the multiple sites in SrGd2O4:Eu3+ has been found to be 12.08 × 10–3% K−1 while using McCumber-Sturge equation to quantify line shift. [ABSTRACT FROM AUTHOR]