Effect of amorphous Cr-Ti texture inducing layer on highly (002) textured large grain Cr_(80)Mn_(20) seed layer for L1_0 ordered FePt-C granular film

摘要

Heat-assisted magnetic recording media has attracted much attention for future hard disk drive owing to the high magnetocrystalline anisotropy of L1_0 ordered FePt(K_u~ 7×10~7 erg/cm~3)In order to improve signal to noise ratio, it is necessary to fabricate the medium in which the grains are magnetically isolated such as FePt-C based granular film. For large perpendicular anisotropy, controlling the c-axis (002) orientation of the FePt, corresponding to the magnetic easy axis, toward normal to the film is required. In general, the preferred crystal orientation of the FePt can be adjusted by means of hetero-epitaxial growth from (002) textured MgO underlayer. However, it is reported that the misalignment of the (002) grains normal to the film is caused by angular distribution of the MgO (002) orientation. Origin of the angular distribution is regarded due to the absence of the epitaxy growth of the MgO underlayer, which is directly deposited on an amorphous film. In this study, method to suppress the angular distribution is proposed by introducing a new concept of layered structure.