FMR and EXAFS modeling of heat-treated Fe-rich and Co-rich TM-M thin films

Ion-beam sputter-deposited alloy films of Co₇₄Fe₆B₁₅Si₅ and Fe₇₅Ni₅B₁₅Si₅ were examined for their magnetic and structural properties. Films were characterized by ferromagnetic resonance, vibrating sample magnetometry, and extended X-ray absorption fine structure (EXAFS) analysis. Using atomic parameters deduced from EXAFS modeling and fitting procedures, magnetic properties were calculated with no adjustable parameters. Correlation between perpendicular FMR measurements and EXAFS first-shell modeling suggests a low-temperature formation of cobalt-borides in the Co₇₄Fe₆B₁₅Si₅ alloy. Annealed Fe₇₅Ni₅B₁₅Si₅ samples did not display evidence of structural and/or magnetic instabilities until the onset of long-range crystallization near T_ann=400 degrees C.