Regulate the microstructure and band gap of $ La_{2} %$ Ti_{2} %$ O_{7} $

Abstract $ La_{2} %$ Ti_{2} %$ O_{7} $ (LTO) dry gel was obtained according to sol–gel technology. Considering that processing temperature could have effect on the microstructure and band gap of LTO, four temperature points, 500 °C, 850 °C, 1000 °C and 1200 °C were selected to dispose gel to acquire...
Ausführliche Beschreibung

Abstract $ La_{2} %$ Ti_{2} %$ O_{7} $ (LTO) dry gel was obtained according to sol–gel technology. Considering that processing temperature could have effect on the microstructure and band gap of LTO, four temperature points, 500 °C, 850 °C, 1000 °C and 1200 °C were selected to dispose gel to acquire LTO powder. The results indicate that except the sample disposed at 500 °C, other three samples are univocal monoclinic structure with space group $ P2_{1} $ which corresponds to the standard card 1950-ICSD. The crystallinity of LTO powders increases with the increase of processing temperature. The distortions of the LTO unit cell at a–b projection plane first decrease and then increase. Adopting the UV–visible reflection spectrums analysis, the band gaps of LTO powders disposed at 500 °C, 850 °C, 1000 °C and 1200 °C are 3.82 eV, 3.99 eV, 4.08 eV and 3.94 eV, respectively. Ausführliche Beschreibung