Magnetic and electrical properties of single-phase, single-crystal Fe16N2 films epitaxiallly grown by molecular beam epitaxy

The average magnetic moment per Fe atom for a single-phase, single-crystal Fe16N2(001) film epitaxially grown on a GaAs(001) substrate by molecular beam epitaxy has been confirmed to be 3.5 mu(B) at room temperature by using a vibrating sample magnetometer (VSM) and Rutherford backscattering. The value was in good agreement with that obtained by using a VSM and by measuring the film thickness (3.3 mu(B) per Fe atom). The saturation magnetization 4 pi M(s) has been found to increase with decreasing temperature, obeying T-3/2 law at lower temperatures. The slope was steeper than that of a pure Fe film, suggesting a lower exchange constant for Fe16N2. The g factor for Fe16N2 has been accurately measured to be 2.17 by using ferromagnetic resonance with changing frequencies of 35.5-115 GHz, which is not unusual compared with the g factor of 2.16 for pure Fe. The resistivity for Fe16N2 has been measured to be around 30 mu Omega cm at room temperature compared with 10 mu Omega cm for pure Fe and decreases linearly with decreasing temperature. The behavior was that for normal metal and nothing unusual was seen. The anomalous Hall resistivity for Fe16N2 was 4X10(-7) V cm/A, which is about three times as large as that for pure Fe. The relationship between the giant magnetic moment and the anomalous Hall resistivity has been clarified yet. (C) American Institute of Physics.