MAGNETIC-ANISOTROPY OF FERROSMECTIC PHASES

A new anisotropic magnetic fluid, called ferrosmectic, is obtained whe n using a colloidal suspension of submicronic magnetic particles (ferr ofluid), as a component in a smectic phase of fluid membranes. These l amellar phases present specific magnetic properties. The anisotropy of their magnetic susceptibilities as a function of particles concentrat ion is studied and interpreted: a microscopic mechanism involving a st eric hindrance between particles and membranes is used to understand t he experimental results.