Strain-inhomogeneity effect on magnetization and low-temperature resistivity of epitaxial Fe(0 0 1) thin films

The influence of incorporating nitrogen and strain-related effects on transport and magnetic properties have been studied in a series of Fe(0 0 1) thin films grown at different temperatures. A minimum in the low-temperature electrical resistivity has been observed for samples grown at intermediate temperatures. In the same low-temperature range, a decrease of the zero-field-cooled magnetization has also been measured. Since those anomalies disappear when cooling under applied magnetic field, it is inferred that they are due to the magnetically inhomogeneous nature of the system. These results suggest that local anisotropy within homogeneous regions competes with thermal fluctuations and exchange coupling between different regions, producing a randomization of the magnetic moments below a critical temperature