Tailoring of Structural and Magnetic Properties of Sputter-Deposited Terfenol-D Thin Films by Optimizing the Substrate Temperature

Abstract

In this paper, sputter-deposited Terfenol-D thin films were grown on MgO/Al2O3 substrates by DC-magnetron sputtering using single target having composition of Tb0.3Dy0.7Fe1.92. The temperature of substrate was purposefully set as 500, 800, and 1000 °C to modulate the structural and magnetic properties of grown films. XRD scans showed that substrate temperature 500 °C was found to be optimum temperature for single phase growth of the Terfenol-D layers. XRD data also demonstrated that higher substrate temperature facilitates the development of secondary phases. Crystallinity of deposited film had been decreased by increasing temperature of substrate. WDS results showed that grown films have compositions near to Terfenol-D target composition. SEM analysis showed that thin films grown at substrate temperature 500 °C have relatively smoother surface when compared with other samples which are grown using relatively higher substrate temperature. The magnetic data demonstrated that the value of saturation magnetization decreased from 1932 to 295 emu/cc as the substrate temperature increased from 500 to 1000 °C, respectively. Hysteresis curves are more tilted for lower temperatures showing ferromagnetic nature of deposited films.