Date of this Version
Cobalt RareEarth (CoR, R = Pr,Sm) thin films on a Cr underlayer have shown promise as future ultra high density magnetic recording media. The activation volume or the magnetic switching volume (v*) is an important consideration for thermal stability and media noise in high density recording media and V* can also provide information about the magnetization reversal behavior in these films. The magnetic switching volume was estimated for the CoPr films with thicknesses from 28 to 639 nm with a Cr underlayer of 80 nm annealed at 500 0C. The measured switching volume ranges from 1.3 to 1.7x10-18 cm3. We have also studied the Cr underlayer thickness and temperature effects on the swithcing volume for the CoSm films.