Uniaxial anisotropy in MgFe2−yAlyO4

Abstract

Single crystals of MgFe_2−yAl_yO₄ (y=0−0.9) grown from PbO flux exhibit stripe−serpentine domains in (100) sections indicating an induced uniaxial anisotropy similar in behavior to that existing in rare−earth garnets. The anisotropy field was found to be less than 4πM_s. The magnetization was found to be a complex function of temperature and aluminum content due to the variable tetrahedral occupation of the Mg²⁺ ion. This latter fact is proposed to account for the uniaxial anisotropy. Other low−moment spinel single crystals were grown with no observation of stripe domains.