Title :
Structure, stress, and magnetic properties of high saturation magnetization films of FeCo
Author :
Vas´ko, Vladyslav A. ; Rantschler, James O. ; Kief, Mark T.
Author_Institution :
RHO, Seagate Technol. LLC, Minneapolis, MN, USA
fDate :
7/1/2004 12:00:00 AM
Abstract :
Thin (∼2000 Å) films of Fe60Co40 have been prepared by sputtering on Si/SiO2, Si/AlOx, AlTiC/AlOx, AlTiC/AlOx/NiFe, and AlTiC/AlOx/NiFeCr substrates using an alloy Fe60Co40 target. The structure of the films was characterized by means of X-ray diffraction and transmission electron microscopy (TEM). Surface roughness was characterized by atomic force microscopy (AFM). Stress, transport, and magnetic measurements were conducted. We observed correlation in the following pairs of properties: coercivity-stress, grain size-stress, and coercivity-grain size. Although individual films had a stress in the wide range of compressive 2.5×1010 Dyne/cm2 to tensile 1.3×1010 Dyne/cm2, which depended to some degree on the material of the substrate and underlayer, we found that biaxial stress and coercivity seem to be described by a general trend, with coercivity being as low as 19 Oe at intermediate tensile stress and as high as 225 Oe at high compressive stress. The unstrained lattice parameter and Young´s modulus of the alloy Fe60Co40 were also determined.
Keywords :
X-ray diffraction; Young´s modulus; atomic force microscopy; cobalt alloys; grain size; iron alloys; magnetic thin films; sputtering; stress-strain relations; surface roughness; tensile strength; transmission electron microscopy; FeCo film; FeCo-AlTiC-AlO; FeCo-AlTiC-AlO-NiFeCr; FeCo-Si-AlO; FeCo-Si-SiO; FeCoAlTiC-AlO-NiFe; X-ray diffraction microscopy; Young modulus; atomic force microscopy; biaxial stress; coercivity-grain size; coercivity-stress; compressive stress; film structure; grain size-stress; high saturation magnetization films; magnetic measurements; magnetic properties; sputtering; stress measurements; stress properties; surface roughness; tensile stress; thin films; transmission electron microscopy; transport measurements; unstrained lattice parameter; Atomic force microscopy; Cobalt alloys; Coercive force; Compressive stress; Iron alloys; Magnetic films; Magnetic properties; Saturation magnetization; Tensile stress; Transmission electron microscopy; Coercivity; FeCo film; Young's modulus; grain size; lattice parameter; sputtering; stress; structure;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2004.832256