X-ray-induced reduction of Sm3+-doped SrB6O10 and its room temperature optical hole burning

We prepared two kinds of Sm-doped strontium borates. When the samples were prepared in air environment, while the Sm3+ ions doped in strontium tetraborate (STB) were well reduced, the trivalent Sm ions were partially reduced in strontium hexaborate (SHB). The SHB was successfully reduced by subsequent x-ray irradiation (SHBX) and showed a strong Sm2+ emission. The photoluminescence, excitation spectrum and spectral hole burning experiments were conducted for the samples. The crystallographic sites of Sm2+ ions were found to be different in the STB and SHBX. Spectral holes were observed at room temperature in both samples STB and SHBX. The measured hole depths were 24% and 63% in STB and SHBX, respectively. As a result, we could obtain effective and novel hole burning material based on the Sm-doped strontium borates with x-ray-induced reduction.