Magnetic properties of Nd-Fe-B nanocomposite films prepared by a new method using pulsed laser deposition

Nanocomposite film-magnets with the thickness of several tens of microns were prepared by the pulsed laser deposition method with a rotating Nd2.6Fe14B/Fe3B composite target. As-deposited films were composed mainly of amorphous Nd-Fe-B and Fe-B phases and exhibited soft magnetic properties. Annealing crystallized the films into the composite state composed of Nd2Fe14B and alpha-Fe/Fe2B. Superior hard magnetic properties were developed, when the calculated thickness of the period of Nd-Fe-B/Fe-B layers is approximately 90 nm. Films annealed in situ by the Joule-heating were prevented from surface oxidation and their magnetic properties were improved compared with those of films annealed with an infrared furnace. The obtained coercivity, remanence and (BH)(max) were 323 kA/m, 1.05 T and 85.7 Urn 3, respectively. The above remanence and (BH) a., values are higher than the corresponding values reported for the film-magnets prepared from a single Nd2.6Fe14B target, Considering the strong spring-back phenomenon and the existence of soft phases in our films, a large rernanence value and resultantly, a large (BH)(max) value of our films can be attributed to the rernanence enhancement based on the effective intergrain interaction. (c) 2005 Elsevier B.V. All rights reserved.