Magneto-optical effects from nanophase alpha-Fe and Fe3O4 precipitates formed in yttrium-stabilized ZrO2 by ion implantation and annealing

Magneto-optically active nanocomposite structures have been created by usin g ion implantation and thermal processing to form precipitated layers of fe rromagnetic alpha-Fe or ferrimagnetic Fe3O4 that are embedded in the near-s urface region of (100)-oriented yttrium stabilized ZrO2 (YSZ). When Fe-impl anted YSZ is annealed at 1100 degrees C in Ar+4%H-2, the redox conditions a re sufficiently reducing so that metallic Fe is the stable phase. At lower temperatures the annealing conditions become less reducing and Fe3O4 become s the stable phase. Transmission electron microscopy and x-ray diffraction studies established that each alpha-Fe or Fe3O4 particle is a single crysta l that is cl crystallographically aligned with respect to the YSZ host. Mag neto-optical effects due to both the alpha-Fe and Fe3O4 nanophase precipita tes were found and characterized using magnetic circular dichroism. These m agneto-optical effects have potential applications in integrated-optical de vices. (C) 2000 American Institute of Physics. [S0003-6951(00)02031-3].