Study On Magnetically Induced Phase Separation In Co-V Based Alloy Thin Films And Its Magnetic Properties

Nowadays,the magnetic recording is one of the most important ways to store information.As the development of computer and internet technology,the data storage with higher density is urgently required.The longitudinal magnetic recording is one way to realize the ultra-high-density storage.This paper described the basic principle and the requirement of magnetic recording materials,and studied the magnetic properties of Co-V base alloys with phase separation induced by magnet, and determined the phase equilibria in the Co-Cr-Ta system.The main contents in the paper are as follows:(1) Some Co-V thin films were prepared by RF magnetron sputtering,and their crystal structure,surface morphology and perpendicular magnetic properties were studied,and the influences of the V contents,temperature and thickness on the magnetic properties of films were analyzed.The experimental results indicates that at 427K there is the best perpendicular magnetic properties in the Co-21V(at.%) film, and its coercive force is 2250 Oe.The rate of hysteresis loop(Mr/Ms) is 0.74,and saturated magnetization(Ms) is 650(emu/cc),which are better than those in Co-Cr films.(2) Some Co-V-Ta thin films were prepared by co-sputtering,and their perpendicular magnetic properties were measured.The influences of Ta contents on crystal structure and magnetic properties in the Co-V-Ta thin films were studied.In addition,the effects of sputtering temperatures and heat treatment on the structure and magnetic properties were also examined.The experimental results indicated that the Co-7.8V-8.9Ta(at.%) thin film has the best magnetic properties,where the coercive force is 2250 Oe,Mr/Ms is 0.75,and Ms is 600 emu/cc.(3) The phase equilibria in the Co-Cr-Ta system at 700℃800℃,900℃and 1100℃were experimentally determined by means of electron probe microanalysis (EPMA) and X-ray diffraction(XRD) on equilibrated ternary alloys.This is first time to establish the phase equilibria in the Co-Cr-Ta ternary system.