Crystal Orientation of CO₃₅Fe₆₅ Thin Film for the GHZ Frequency Use with More Than 10 GHZ

Abstract

  The Co₃₅Fe₆₅ magnetic films with Ru underlayer were fabricated using a special RF-magnetron sputtering method and characterized. The underlayer coating effect of improving soft magnetic properties for the GHz frequency use was investigated relating to the surface roughness and thickness of Ru underlayer and the crystalline structure and orientation of as-deposited magnetic layers.
  The coating of the underlayer with thickness of 10-30 Å was so much effective to achieve a high uniaxial magnetic anisotropy field of 1000 Oe with the low coercivity less than 10 Oe for the higher driving frequency (ferromagnetic resonance frequency over 10 GHz), by inducing about 1% elongation of lattice parameter in the c direction of_the bct Co-Fe magnetic phase, preferred crystalline orientation of (110), (200) of the bct Co-Fe magnetic phase, and about 60% decrease of crystallite size in the Co-Fe layer. The (110) plane was preferentially parallel to the film plane and the elongated lattice in the c direction was oriented preferentially parallel to the easy magnetic axis in accord with the direction of the (200) plane space.