Abstract
NdFeB thin films with perpendicular c-axis orientation texture have been studied as promising candidates for ultrahigh-density recording media because of their high magneto crystalline anisotropy and large saturation magnetization. NdFeB thin films deposited on W underlayer with composition of Nd18Fe76B6 and a thickness of 15 nm exhibited perpendicular coercivity as high as 6.0 kOe. In our case, NdFeB thin films deposited on W underlayer need substrate temperatures of 440°C to crystallize Nd2Fe14B and to have high magneto crystalline anisotoropy. Reducing substrate temperature is instructive for sputtering process and decreasing grain size. It was found that Cu addition to NdFeB phase could be reduced the substrate temperature from 440°C to 380°C with 2.7 at.% of Cu. The perpendicular coercivity and squareness for NdFeB thin film with the thickness of 15 nm and 2.7 at.% of Cu were 4.7 kOe and 0.95, respectively.
