Magnetic properties of amorphous BiFeO3-PbZrO3 sputtered films

Abstract

Amorphous thin films of (1−x)BiFeO3-xPbZrO3 for x=0.1–0.9 have been prepared by the technique of rf sputtering and the effects of sputtering conditions and annealing at high temperatures on magnetic properties of such films have been studied through magnetization measurements. A sintered polycrystalline target was used to sputter 0.2–1.4-μm-thick films in oxygen, argon, and mixed oxygen and argon atmospheres onto glass and silicon substrates. As-sputtered films are x-ray amorphous and show paramagnetism at room temperature. A hard-ferromagnetlike character with remanence is observed in films annealed at temperatures Ta above 500 °C. The room-temperature magnetization increases with further increase in Ta and shows a maximum for Ta = 650 °C. A partial crystallization occurs for Ta ≳ 650 °C and is accompanied by a decrease in the magnetization. The magnetization for annealed samples shows a dependence on x, with a minimum of 0.6 emu/g for x=0.9 and a maximum of 40 emu/g for x=0.5.