Self‐Trapped Particles in Complex Oxide Crystals

Abstract Self‐trapped hole (STH) and self‐trapped exciton (STE) states which are formed in Y 3 Al 5 O 12 , Y 2 SiO 5 , and TR 2 Si 2 O 7 crystals under γ‐irradiation in the temperature interval of 77 to 200 K are investigated. The STH is shown to be molecular O , absorbing at 1.6 eV (for Y 3 Al 5 O 12 ) and at 1.65 eV (for Y 2 SiO 5 ) and causing the eleven‐component EPR signal; the corresponding STE emits at 3.9 and 3.6 eV. In metal‐doped crystals the exciton and hole delocalization lead to a decreasing of the emission energy, to a short‐wave shift of the absorption band, and to the growth of the anneal temperature. At the self‐localization temperature excitons are proved to migrate by jump diffusion and to transfer energy to the impurity ions exciting their emission.