Deposition of NiAl thin films from NiAl compound target fabricated via combustion synthesis

A dense and homogeneous NiAl compound target has been fabricated via a novel, one-step process -- combustion synthesis simultaneously coupled with hot pressing. NiAl thin films have been successfully deposited from this NiAl target onto various substrates, including stainless steel, glass, and Si<100> wafer, by using RF magnetron sputtering. The films have been characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and scanning transmission electron microscopy. The texture, composition, and microstructure of the NiAl films change with the deposition power used. The NiAl thin films deposited using 500 W RF power exhibited a microstructure of a 0.5-0.7 μm amorphous layer adjacent to the substrate and a dense and columnar zone T crystalline microstructure which had a preferred orientation [110] which is the close-packed direction for NiAl. The results confirm the feasibility of producing high quality NiAl thin films from a NiAl compound PVD target. By successfully manipulating the synthesis parameters of the target and deposition parameters of the film, a NiAl thin film can be designed to meet the needs for various high temperature applications.