Enhanced magnetic properties of nanophase SmCo5 film dispersions

Nanophase dispersions of SmCo₅ in either an Al, Co, Co-Fe, Si, or Ti matrix have been synthesized by using pulsed laser deposition, PLD, to deposit the SmCo aggregated grains while simultaneously sputtering either Al, Co, Co_0.5Fe_0.5, Si, or Ti. Substrate temperatures of 375 to 435°C were sufficient to form SmCo₅ grains with the c-axes aligned onto the substrate plane for low matrix concentrations in each case with intrinsic coercivities of about 15 kOe for approximately 5 at.% additional matrix element. At higher matrix element concentrations, for Al, Co, and Co-Fe in-plane aligned grains were obtained to at least 20 at.% matrix element. For Al and Co additions, the intrinsic coercivities followed the equation, _iH_c=22.0 kOe-1.77*(at.%)+(6.4E-2)*(at.%)² -(8.2E-4)*(at.%)³ where at.% is the added Al or Co atomic percentage. As previously shown special PLD conditions including shadowing, a narrow range of laser pulse rates, and high laser pulse energies of approximately 1 J per pulse were required to obtain the aligned high coercivity SmCo₅ grains. For the dispersions, smooth single phase type hysteresis loops were measured for each type of dispersed system. Less than 1 micrometer thick films of Al and in-plane aligned SmCo₅ grain dispersions were unaffected by heating in air for 30 minutes to 300°C. The SmCo₅/(Co,Co-Fe) dispersions exhibited elevated remanence and saturation values with in-plane squareness greater than 0.8