Structural and optical properties of Eu-doped at the site of Sr and Sn in Sr_2SnO_4 layered perovskite

摘要

The structural and emission analysis of Sr_2SnO_4, Sr_(1.99)Eu_(0.01)SnO_4, and Sr_2Sn_(0.99)Eu_(0.01)O_4 were analysed in detail. The thermal analysis of the mixture of raw materials reveals the reaction among the raw materials takes place around 1000°C. The Reitveld refinement of the x-ray diffraction data shows the solubility of Eu on both site of Sr_2SnO_4. Higher crystallite size and lattice strain were observed for Sr_(1.99)Eu_(0.01)SnO_4 than Sr_2Sn_(0.99)Eu_(0.01)O_4, because Eu~(3+) acts as donor at Sr~(2+) site while as acceptor at Sn~(4+) site. Absences of any band associated with raw materials in Raman spectrum also confirm the monophasic nature of the sample. The photoluminescence (PL) spectra of Eu-doped samples exhibits strong peak at 612 nm ascribed to electric dipole transition ~5D_0→~7F_2 of Eu~(3+) shows higher peak intensity and width for Sr_(1.99)Eu_(0.01)SnO_4 than Sr_2Sn_(0.99)Eu_(0.01)O_4.