Synthesis and Preparation of Lanthanum Aluminate Target for Radio‐Frequency Magnetron Sputtering

A polycrystalline LaAlO 3 target for the radio‐frequency (rf) magnetron sputterings of LaAlO 3 thin films has been prepared. These films serve as a buffer layer for high‐ T c YBa 2 Cu 3 O 7– x superconducting thin films on Si. Synthesis of lanthanum aluminate powder from a mixture of La 2 O 3 and Al 2 O 3 powders was performed by calcining from 1000° to 1600°C in air. Characterization of the calcined powders by X‐ray diffraction indicates that full development of LaAlO 3 phase was evident in the sample calcined for 3 h at 1600°C in air. A polycrystalline LaAlO 3 target was prepared by heat treatment at 1500°C for 2 h in air after pressureless sintering at 1750°C for 3 h in Ar. Thin films of the LaAlO 3 on Si (100) were obtained by rf magnetron sputtering using the target and oxygen‐annealing the as‐deposited films.