Co80Pt20 thin films on Cr, Cr80V20, or Cr90Ti10 underlayers were studied to improve the magnetic properties for permanent magnetic stabilization layer application in anistropic magnetoresistance/giant magnetoresistance devices. A significant improvement of nearly 15% in coercivity was achieved for CoPt films on CrTi underlayer, when compared to either Cr or CrV underlayer. X-ray diffraction pattern analysis showed that CrTi underlayer increased the intensity of CoPt (10.0) indicating enhanced crystallographic in-plane texture. With CrTi underlayer, CoPt coercivity increased linearly as Mrt was reduced from 4.3 to as low as 0.4 memu/cm2. The squareness and S* values started to drop sharply when the Mrt of CoPt film decreased to below 1.0 memu/cm2. In addition to 15% higher coercivity, another important property of CrTi/CoPt was that for CrTi underlayer thickness between 3 and 20 nm very little change in the coercivity, squareness, and S* of CoPt layer was observed. The CoPt films showed excellent corrosion resistance towards high humidity and good thermal stability up to 300 °C. The CoPt films with the underlayer of CrTi and CrV showed slightly less corrosion resistance towards industrial pollutants than those with no underlayer and Cr underlayer. © 1999 American Institute of Physics.