Energy product enhancement of CoPt films by the alloy addition of Ti

Ternary (Co48Pt52)(100-x)Ti-x (x = 0, 0.8, 3.7, 5.3) films were deposited on quartz substrates by RF sputtering at the annealing temperatures T-a = 500-800 degrees C. The addition of Ti was found to suppress the formation of the CoPt-ordered phase. The coercivity squareness parameters (S*) were also increased with the addition of titanium. TEM observations indicated that the Ti addition significantly reduces the grain size of the CoPt film, thus enhances the exchange interaction between the magnetic grains. The advantages result in the increase of (BH)(max) values from 2.91MGOe for x = 0.0 to 6.09 MGOe for x = 5.3 after the samples is annealed at an optimum temperature of 700 degrees C. (C) 2006 Elsevier B.V. All rights reserved.