Magnetic dead layers in NiFe/Ta and NiFe/Si/diamond-like carbon films

NiFe, Ta films were fabricated by ion beam deposition (IBD) and diamond-lik e carbon (DLC) films by ion beam chemical vapor deposition (IB-CVD) and fil tered cathodic arc (FCA) process. Magnetic dead layers at interfaces of Ta/ NiFe/Tn and NiFe/Si/DLC trilayer films were determined by characterizing ma gnetic flux loss using a B-H loop tracer. Dependence of magnetic dead layer on ion beam voltage and thicknesses of Ta, DLC, and Si layers was investig ated. It is found that the thickness of magnetic dead layer increases monot onously with increasing ion beam voltage for Ta and DLC film depositions. T he magnetic dead layer of 4-6 Angstrom thick forms at Ta/NiFe and NiFe/Ta i nterfaces at an ion beam voltage of 1000 V, which can be attributed to the atomic intermixing of incoming energetic adatoms with atoms of grown films at interfaces. Direct ion beam deposition of the DLC film in NiFe/Si/DLC la yered structure gives rise to a magnetic thickness loss of 12-18 Angstrom. Transmission electron microscopy cross-sectional observations have confirme d the formation of an amorphous-like interfacial layer, as a result of carb onization or silicidation of NiFe at interfaces of the trilayer film. (C) 2 000 American Institute of Physics. [S0021-8979(00)87408-3].