Investigation of the Magnetic Field Angle Dependence of Resistance and Activation Energy of DC-sputtered Bi-2223 Thin Film

Abstract

This study deals with not only the effect of the applied magnetic field at different angles on critical temperature (T c) and activation energy (U 0) but also the surface quality of the Bi-2223 thin film produced by direct current magnetron reactive sputtering method via resistance measurements, X-ray diffractometer (XRD) and atomic force microscopy (AFM) investigations. The results indicate that the T c and U0 decrease with increase in the applied magnetic field. Furthermore, XRD measurement, reinvestigated to identify the phase composition of the sample, shows that (0 0 l) peaks are dominant features and the Bi-2223 phase is more widespread than the Bi-2212 phase. As for microstructural properties of the film, AFM image shows that the film thickness is about 900 nm when average roughness and root mean square (rms) roughness are about 89.7 and 96.3 nm, respectively. Based on AFM observations, the high surface roughness and irregular structure are obtained on the surface of the sample. The surface skewness and kurtosis roughness from the height asymmetries are also calculated to be about 1.635 and 3.107, respectively. According to the positive skewness and high kurtosis, the film surface is obtained in high quality. Moreover, the observed degradation in critical temperature and activation energy with increasing the applied magnetic field is discussed to be associated with AFM observations. As a result, despite the high surface roughness and irregular structure, the sample produced in this work is suitable for application in technology and industry owing to the height asymmetries.