Microstructure and dielectric properties of Ba1−xSrxTiO3 films grown on LaAlO3 substrates

• Published in: Applied physics letters Vol. 77; no. 8; pp. 1200 - 1202
• Main Authors: Gim, Y., Hudson, T., Fan, Y., Kwon, C., Findikoglu, A. T., Gibbons, B. J., Park, B. H., Jia, Q. X.
• Format: Journal Article
• Language: English
• Published: 21-08-2000
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.1289272

We report a systematic study of the microstructure and dielectric properties of barium strontium titanate, Ba1−xSrxTiO3, films grown by laser ablation on LaAlO3 substrates, where x=0.1–0.9 at an interval of 0.1. X-ray diffraction analysis shows that when x<0.4, the longest unit-cell axis is parallel to the plane of the substrate but perpendicular as x approaches 1. Dielectric constant versus temperature measurements show that the relative dielectric constant has a maximum value and that the peak temperatures corresponding to the maximum relative dielectric constant are about 70 °C higher when x⩽0.4 but similar when x>0.4, compared with the peak temperatures of the bulk Ba1−xSrxTiO3. At room temperature, the dielectric constant and tunability are relatively high when x⩽0.4 but start to decrease rapidly as x increases.