Effects of sputtering conditions on texture, microstructure and magnetic properties of the CoCrPt/NiAl thin films

The effects of sputtering argon pressures and sputtering power on the microstructure, texture and magnetic properties of NiAl underlayers on CoCrPt films were investigated. In this paper, the relationship between the sputtering conditions, microstructure, crystallographic texture and magnetic properties of these thin films will be discussed. By controlling the sputtering pressure and sputtering power, the texture and microstructure of NiAl underlayers were found to vary. This in turn was found to influence the magnetic properties of CoCrPt thin films. It was found that 10 mtorr is the optimum pressure to deposit the NiAl thin films to obtain the best magnetic properties for our system. At this argon pressure, the coercivity reached a maximum value because of the strongest CoCrPt (10 (1) over bar 0) texture and smallest grain size. At lower argon pressures (< 10 mtorr), NiAl tended to have a (110) texture reducing the CoCrPt (10 (1) over bar 0) texture, which in turn reduced the CoCrPt coercivity and S*. Also, high NiAl deposition pressures (>30 mtorr) yielded larger grains and a weaker CoCrPt (1 0 (1) over bar 0) texture, thereby decreasing the coercivity of the CoCrPt films. Increasing the sputtering power has been found to increase the CoCrPt coercivity and S* value. However, the grain sizes of the CoCrPt/NiAl thin films deposited at higher sputtering power were larger than those obtained at lower sputtering power.