The effects of varying the laser power and the spot diameter of a laser beam on the magnetic properties, morphology, and deposition rate of Nd-Fe-B thick-film magnets fabricated by pulsed laser deposition (PLD) were investigated. Reducing the laser fluence on the target reduces the remanence and increases the Nd content and consequently the coercivity of the prepared films. The spot size of the laser beam was found to affect the film surface morphology, the deposition rate, and the reproducibility of the magnetic properties of the prepared films. Reducing the spot size reduces the number of droplets and the reproducibility of the magnetic properties and increases the droplet size. Controlling the spot size of the laser beam enabled us to maximize the deposition rate. Consequently, a coercivity of 1210 kA/m and a remanence of 0.51 T were obtained at a deposition rate of 11.8 lm/(hÁW). This deposition rate is 30% greater than the highest previously reported deposition rate by PLD.

multi-layered thick film-magnets were synthesized by pulse laser deposition (PLD) method from a -Fe composite target. In order to improve magnetic properties and their reproducibility, effects of the stacking period of layers, , the target-substrate distance, , and the laser beam energy on a target, , on them were studied. The reproducibility of magnetic properties was improved significantly by decreasing . In particular, the standard deviation of the Nd content was suppressed within 3%, when was reduced from a value higher than 200 to 25 . An increase in and selection of a suitable value improved the maximum energy product . The largest value obtained in this investigation was 112 , which is higher than the values reported previously for isotropic film-magnets thicker than 10. Origins of superior magnetic properties were discussed from the viewpoints of suitable interlayer exchange interaction between Nd-Fe-B and -Fe layers and morphology of prepared film-magnets.Index Terms-Layered structure, nanocomposite magnet, Nd-Fe-B, pulse laser deposition (PLD) method, thick film-magnet.

Nd-Fe-B/α-Fe multi-layered nanocomposite film-magnets were prepared from a rotating Nd 2.6 Fe 14 B/α-Fe composite target by the pulse laser deposition method with a Nd-YAG laser (λ=355 nm). The prepared film-magnets were composed of approximately 800 layers with the thickness of about several tens nanometre, and exhibited hard magnetic properties after annealing. The laser power for the ablation of the target was varied between 3 and 7 W, and it was found that the composition, magnetic properties, and the surface roughness of the prepared films depend on the laser power. A reduction in the laser power caused increases in remanence and the maximum energy product (BH) max as well as decreases in Nd content and coercivity of the films. All the samples had Nd-poor compositions compared with that of the Nd 2.6 Fe 14 B target and the Nd-contents of the films deposited with laser power of 3 W were less than that of the stoichiometric composition of Nd 2 Fe 14 B. The highest (BH) max and remanence values were obtained for a film deposited with laser power of 3 W, and were 90 kJ/m 3 and 1.0 T, respectively. The obtained high remanence value is discussed from the viewpoint of the remanence enhancement as well as the large saturation magnetization of α-Fe .