Noncollinear Spin Arrangement in Ultrafine Ferrimagnetic Crystallites

Abstract

M\"ossbauer-effect measurements on extremely small (\ensuremath{\sim}60 \AA{}) crystallites of $\ensuremath{\gamma}\ensuremath{-}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$ show that the spin configuration differs from the N\'eel type found in large crystallites. It is proposed that the ions in the surface layer are inclined at various angles to the direction of the net moment.