EFFECTS OF LATTICE MISMATCH STRAIN ON Fe8N-Fe16N2 PHASE TRANSFORMATION AND AGING PROCESS

It has been debated for decades whether  ”-Fe 16 N 2 has a giant saturation magnetization, which couldn’t be predicted by the traditional band magnetic theory. Because of a lot of previous inconsistent research results in the past 40 years,  ”-Fe 16 N 2 has been regarded as a debatable mystery material in magnetic research community. Recently, Wang’s group has successfully rationalized a partially localized 3d electron model based on the first principles calculation and predicted the existence of the giant saturation magnetization in  ”-Fe 16 N 2 . Furthermore, we have synthesized FeN thin films with partially ordered  ”-Fe 16 N 2 phase on GaAs substrate with Fe as the underlayer. Our repeatable experimental results proved the existence of giant saturation magnetization of partially ordered  ”-Fe 16 N 2 phase. However, there has been a critical question on this topic for any experimentalist to answer, which has actually bothered magnetic researchers for almost four decades. Why did most experimental research groups not succeed to report the giant saturation magnetization value even with their fabricated FeN films with observed  ”-Fe 16 N question has answered in this MS thesis work. The effect of the initial strain on the phase transformation between Fe 8 N and Fe 16 N 2 , which is caused by the lattice mismatch between the layer and its growth template, was investigated. A model was proposed, based on the

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