Nd–Fe–B Thin Films with Perpendicular Magnetic Anisotropy and High Coercivity Prepared by Pulsed Laser Annealing

概要

論文の詳細を見る
Amorphous, as-deposited Nd–Fe–B films prepared by RF-sputtering were annealed by irradiating pulsed KrF excimer laser (248 nm). A pulse of 20 ns in width and 4 kJ/m2 in power density was irradiated onto a 2 μm-thick as-deposited film kept at 400°C. It is observed that, by a single shot of the pulse, Nd2Fe14B $\Phi$ phase crystallized with prominent texturing of $c$-axis along the film normal. Annealed films showed excellent magnetic characteristics; $M_{\text{s}}=0.978$ T, $M_{\text{r}}=0.906$ T, ${_{\text{i}}}H_{\text{c}}=1272$ kA/m, and $(BH)_{\text{MAX}}=161$ kJ/m3. This process is also found to be successfully applicable to a 20 μm-thick film. Using 2 μm-thick as-deposited film kept at 400°C, micro-magnet patterns of 100 μm in width and 1–2 mm in length were fabricated by irradiating a 20-ns pulse shot through a patterned mask. The patterned area revealed that magnetizations are directed along the film normal with coercivity higher than 1200 kA/m.
2003-11-15