Yttria-stabilized zirconia: a suitable substrate for c-axis preferred Nd–Fe–B thin films fabricated by pulsed–laser deposition

Abstract

Yttria-stabilized zirconia (YSZ) substrates were used to fabricate Nd–Fe–B thin films from a Nd 13.5Fe 80.0B 6.5 target by pulsed-laser deposition at temperature of 500–690°C and under varied ambient Ar pressure. Grown on (1 0 0) YSZ, the main phase in as-deposited Nd–Fe–B films is tetragonal Nd 2Fe 14B, which tends to orient its c-axis perpendicular to the substrate surface. YSZ is found to be chemically compatible with Nd–Fe–B film, yielding a sharp film/substrate interface and a short inter-diffusion length (30–40 nm) of Y and Zr in the film. Large fluctuations of magnetic properties in terms of 4π M s (0.3–1.5 T), M r/ M s ratio (0.4–0.7) and H c (200–1050 Oe) associated with fluctuation in surface morphology and surface particle density were observed, indicating that magnetic properties of the films depend greatly on their microstructure rather than chemical composition. YSZ substrate appears to be a suitable candidate for the study of structure dependence on the magnetic property of Nd–Fe–B films. Optimization of the fabrication parameters for Nd–Fe–B film on YSZ may lead to novel applications, where YSZ serves as both diffusion barrier and lattice matching buffer on substrates such as Si.