Nano-grain Al2O3 crystals grown by sputtering of aluminium on CoCrPt thin films for potential application in ultra-high-density recording media

Designing supraceramic assemblies based on Al2O3 has remained a challenge due to the problems associated with the suitable dispersion in neat compounds and ability to control the preferred orientation in a unique fashion. Herein, granular HCP-(CoCrPt)100−X(Al2O3)X (X represents the percent weight) thin films with Si(1 0 0) substrates have been fabricated using sputtering technique followed by annealing treatment. Structural and magnetic properties of thin film have been investigated for potential application in magnetic recording media. It was shown that coercivity increased from 0.5 to 2.5 kOe by increasing the nano-grain Al2O3 content in the CoCrPt magnetic layers. In CoCrPt-Al2O3 thin films coercivity of 2.5 kOe has been obtained with increasing the Al2O3 content from 3 to 13 wt.% in the annealed thin films. The structural properties of the samples were studied using X-ray diffraction (XRD) and transmission electron microscope (TEM) equipped with selected area electron diffraction (SAED). The magnetic properties of the samples were measured with a vibrating sample magnetometer (VSM). The VSM results showed that the HCP-CoCrPt-Al2O3 granular films are a promising candidate for ultra-high-density recording media because of its low Al2O3 content and simple manufacturing process.