Ferrite thin film for high-frequency devices and production method thereof

Abstract

The present invention provides a Y-type hexagonal ferrite thin film suitable for high frequency devices, having a crystal structure with the c-axis oriented perpendicular to the surface of the thin film. The present invention also provides a method of producing the Y-type hexagonal ferrite thin film, comprising the steps of preparing a viscous solution containing a metal-organic complex which is formed using a primary component including a Fe +3 ion, and a secondary component including a Ba 2+ ion, at least one transition metal ion selected from the group consisting of Fe 2+ , Co 2+ , Ni 2+ , Zn 2+ , Cu 2+ and Mn 2+ ; and optionally at least one metal ion selected from the group consisting of Sr 2+ , Ca 2+ and Pb 2+ , forming a film having a Y-type ferrite composition on a surface made of noble metal through a coating process using the viscous solution, and burning the film at a temperature of 750° C. or more.

1 . A method of producing the Y-type hexagonal ferrite thin film composite, comprising the steps of: 
 preparing a viscous solution containing a metal-organic complex which is formed using a primary component including a Fe +3  ion, and a secondary component including a Ba 2+  ion and at least one transition metal ion selected from the group consisting of Fe 2+ , Co 2+ , Ni 2+ , Zn 2+ , Cu 2+  and Mn 2+ ;    forming a film having a Y-type ferrite composition on a surface made of noble metal, by use of said viscous solution; and    burning said film.    
   
   
       2 . The method as defined in  claim 1 , wherein said secondary component further includes at least one metal ion selected from the group consisting of Sr 2+ , Ca 2+  and Pb 3+ .  
   
   
       3 . The method as defined in  claim 1 , wherein said preparing step includes the step of adding organic acid and polyol to a solution of material prepared using water-soluble compounds Ba, Zn and Fe as a starting material to form said metal-organic complex constituting said viscous solution, wherein said viscous solution is formed as a film having a composition of Y-type Ba 2 Zn 2 Fe 12 O 22  on said surface made of noble metal and then burnt.  
   
   
       4 . The method as defined in  claim 1 , wherein said burning step is performed at a temperature of 750° C. or more.