Optical, thermal, electrical and morphological study of La1-xCaxGaO3-δ (x=0, 0.05, 0.10, 0.15 and 0.20) electrolyte

La1-xCaxGaO3-delta (x=0, 0.05, 0.1, 0.15 and 0.2) perovskites have been prepared by solid state method in which solid solubility limit was up to x=0.1. The structural modification in the parent LaGaO3 structure with Ca-doping is discussed using X-ray diffraction study. In addition, the optical band-gap change and confirmation of disorder was investigated using diffused reflectance UV-vis spectral analysis. Lattice expansions and intermediate phase transformations with the increase in Ca-content and temperature are verified using dilatometric study. The electrochemical properties of these materials in air are characterized using impedance spectroscopy measurements. The morphological features are investigated using scanning electron microscopy. La1-xCaxGaO3-delta as an electrolyte shows highest conductivity among the investigated LCG systems in intermediate temperature range (600-800 degrees C). Beyond 10 mol% of Ca-content in LCG system, the conductivity decreases due to formation of secondary phases blocking the grain interface region. (C) 2016 Elsevier Ltd. All rights reserved.