(066003)Revisiting Y_3Al_(5?x)Ga_xO_(12) Solid Solutions Doped with Chromium Ions: Effect of Local Symmetry on Thermal Quenching of Cr~(3+) and Cr~(4+) Ions

摘要

The oxidation of chromium ions to the 4+ state in phosphors doped with Cr~(3+) ions is often considered negative due to the activation of the parasitic Cr~(3+)→Cr~(4+) luminescence quenching channel. However, in this paper, a systematic study of the effect ofhost material stoichiometry on the spectroscopic properties of Cr~(4+) in Y3Al5?xGaxO12 is investigated to develop ratiometric luminescence thermometers. Correlations between the structural properties of the host and the luminescence thermal quenchingprocess of Cr~(4+) ions emission associated with the 3 B2→3 B1 electronic transition enabled the development of a luminescence thermometer exploiting the ratio of Cr~(3+) to Cr~(4+) emissions with a relative sensitivity of 2.04%K~(?1) . The studies carried out enabled a better understanding of the formation processes of Cr~(4+) ions.