Microstructure and magnetic properties of CoCrPt/Cr films on ultrasmooth NiP/AlMg substrates

Investigation of the correlation between the microstructure and magnetic properties of Co68Cr20Pt12/Cr thin films which;were sputter deposited under different conditions onto 95 mm ultrasmooth NiP/AlMg disk substrates (R(a) similar to 2 Angstrom) has been carried out. Grain morphology characteristics of the films and disk surface roughness were studied by transmission electron microscopy (TEM) and by atomic force microscopy. Tilted-specimen electron diffraction patterns were used to determine the crystallographic texture of the films. The low coercivity of the disks deposited at 100 degrees C preheated substrates is attributed to the randomly oriented grains of the CoCrPt/Cr layers. Enhancement of the coercivity of the disks deposited on 220 degrees C preheated substrates is thou,bht to be mainly due to the (<11(2)over bar 0>)CoCrPt/(002)Cr crystallographic texture and uniformly distributed grains which are equiaxed in shape. The strength of the (<11(2)over bar 0>)CoCrPt/(002)Cr texture can be modified by the Ar gas pressure during the deposition of the Cr underlayer. (C) 1996 American Institute of Physics.