Magnetizable device

Abstract

A composition that includes a plurality of uniformly sized ferri- or ferromagnetizable particles, each particle having a largest dimension no greater than about 100 nm and being at least partially encased within an organic macromolecule, is disclosed herein.

1 . A magnetizable device which comprises a magnetic layer composed of domain-separated, ferromagnetic particles each of which has a largest dimension no greater than 100 nm.  
     
     
         2 . Magnetic recording medium which includes a magnetizable layer thereon, wherein said magnetizable layer comprises a plurality of ferromagnetic particles each having a largest dimension no greater than 100 nm, and each of which particles represents a separate ferromagnetic domain.  
     
     
         3 . Magnetic recording medium according to  claim 2 , wherein the distance between adjacent ferromagnetic domains is at least 2 nm.  
     
     
         4 . Magnetic recording medium according to  claim 2  or  3 , wherein the distance between adjacent ferromagnetic domains is no greater than 10 nm.  
     
     
         5 . Magnetic recording medium according to  claim 1 ,  2 ,  3  or  4 , wherein each ferromagnetic particle is encased within an organic macromolecule.  
     
     
         6 . Magnetic recording medium according to  claim 5 , wherein each ferromagnetic particle is encased within the cavity or opening of a protein macromolecule.  
     
     
         7 . Magnetic recording medium according to  claim 6 , wherein each ferri- or ferromagnetic particle is encased within an apoferritin protein.  
     
     
         8 . A magnetic composition comprising a plurality of ferromagnetic particles each of which is bound to an organic macromolecule, and each of which ferromagnetic particles has a largest dimension no greater than 100 nm.