Magnetic properties of ion beam deposited CoPt and CoCrPt films for hard bias application in high density magnetoresistive heads

We have observed a 30% of enhancement in coercivity, H/sub c/, or a 40% increase in remnant magnetization in ion beam deposited (IBD) Cr/CoPt films as compared to IBD Cr/CoCrPt films. In addition, the magnetic properties of these hard bias films exhibit a strong dependence of on substrate and underlayer. Higher coercivity values associated with enhanced hcp Co (101~0) crystallographic orientation were measured in films grown on substrates in the preference order of glass, Si/Al/sub 2/O/sub 3/ and Si. CoPt films grown on CrV underlayer show lower H/sub c/ values than films deposited on Cr underlayer. H/sub c/ exhibits a maximum with increasing Cr underlayer thickness for both Cr/CoPt and Cr/CoCrPt films. This Cr thickness dependence of H/sub c/ is correlated well with that of Co (101~0)/(0002) X-ray diffraction peak intensity ratio, indicating the role of crystallographic texture in control of coercivity of IBD hard bias films.