Effect of variation in nitrogen concentration on magnetic properties of Al-N alloy thin films

In the present work the effect of variation in nitrogen concentration on magnetic properties of Al-N alloy thin film has been reported. The AlN films were deposited by RF magnetron sputtering of Al target using a gas mixture of ultra-high pure (99.999%) Ar and N2. Five films were deposited, by varying the nitrogen concentration in gas mixture as 0% (Pure Ar), 5%, 20%, 50% & 100% (Pure N2). All the five films are amorphous in nature. The density of the films increases from 2.18 gm/cc (close to bulk Al density) to 3.24 gm/cc (close to bulk AlN density), indicating increase in formation of Al-N sites with increasing nitrogen concentration. Magnetization measurement on all the five films exhibit hysteresis loop along with paramagnetic or diamagnetic contribution. The observed variation in magnetic properties with increasing nitrogen concentration has been discussed.