Magnetic interactions and thermal stability in CoSm thin films

We report a systematic experimental study of magnetic interactions and thermal stability in very thin films of CoSm fabricated by DC magnetron sputtering on glass substrates, CoSm/Cr films with CoSm thickness 6 to 14 nm yield high remanent coercivities Hcr < 3.8 kOe and low remanent moment thickness product, Mr<delta> < 0.44 memu/cm(2). The magnetic interactions are dominated by exchange coupling, decreasing with increasing thickness, Thermal stability as measured by magnetic viscosity and dynamic coercivity decreases with film thickness, but according to current criteria, CoSm films of down to a thickness of about 8 nm would be stable.