OBSERVATION OF PERPENDICULAR ANISOTROPY IN GRANULAR MAGNETIC SOLIDS

Granular Co-Ag materials with low Co contents exhibit giant magnetores istance and single-domain magnetic properties. In this paper, we discu ss unusual hysteresis behavior that we have observed in Go-rich sample s, where the magnetization is approximately linear with the applied fi eld up to saturation, and the coercivity and remnant magnetization are both nearly zero. We attribute this unusual behavior to a perpendicul ar anisotropy that depends on the nanostructure in the phase-segregate d materials. These results are corroborated by magnetic domain imaging using scanning electron microscopy with polarization analysis. (C) 19 96 American Institute of Physics.