Effects of pH Value on Preparation of La0.65Sr0.35MnO3 by Sol-Gel Process

Abstract:

La0.65Sr0.35MnO3 was prepared at different pH values by sol-gel method. The phase composition of the as-received powder was measured using X-ray diffraction. The particle size and morphology were observed by SEM. The results show that the samples called manganites have single perovskite structure and homogeneous particle size distribution when the pH value is controlled near 0.5 and 8.0 during the sol-gel process. The layer-shaped gel forms in the system when pH=0.5. However, the three-dimensional reticulate gel occurs when pH=8.0. The homogeneous distribution of La, Sr and Mn ions in the gel benefits avoiding the deviation of the chemical composition of manganites and the agglomeration of the powder in the following heat treatment.

Key words:sol-gel process; pH value; manganites