Effect of carbon and post-annealing treatment on magnetic properties of high-quality iron thin films

Abstract: High-quality (110) Fe films with thickness of 200nm were grown on Al2O3 (0006) substrates by low-pressure metal organic chemical vapor deposition (LP-MOCVD). The effects of residual carbon and post-annealing treatment on magnetic properties of Fe films were studied. X-ray photoelectron spectroscopy (XPS) measurements revealed that almost all the interstitial carbon atoms in Fe films can be removed by annealing at temperature of 600°C. Vibrating sample magnetometer (VSM) showed that the in-plane (out-of-plane) coercivity of the film annealed at 600°C is clearly larger (smaller) than that of as-grown one, which can be assigned to the tensile stress relaxation due to the removal of carbon. As the annealing temperature increased from 600 to 750°C, the in-plane coercivity decreased while the out-of-plane coercivity increased. Meanwhile, the in-plane remanence ratios increased rapidly with the increase of annealing temperature, but the out-of-plane remanence ratios changed slightly. The origin of the changes of magnetic properties with annealing temperatures was discussed. [Copyright &y& Elsevier]