Magneto-optical recording medium and magneto-optical recorder using the medium

Abstract

A Co thin film 14 is formed through evaporation on a Si substrate 10 having a Cu sheet layer 12 between the film 14 and the substrate 10. The Si substrate 10 with an orientation ( 100 ) or ( 111 ) is used. The thickness of the Cu seed layer ( 12 ) and the Co thin film ( 14 ) are both approximately 100 nm. The Co thin film ( 14 ) is a single crystal thin film having a face-centered cubic lattice structure with an orientation of ( 100 ) or ( 111 ). The thus structured Co thin film 14 has the maximum 0.4° polar Kerr rotation angle with respect to ultraviolet light having a wavelength of 200 - 230 nm.

1 . A magneto-optical recording medium for recording information by utilizing magneto-optical effects of a metallic thin film; 
 the magneto thin film being a Co 75 Pt 25  alloy crystalline thin film, and    the magneto-optical effects being a polar Kerr rotation angle and/or Kerr ellipticity which have/has an absolute value of 0.1° or over with respect to ultraviolet light having a wavelength of 400 nm or less.    
     
     
         2 . A magneto-optical recording medium according to  claim 1 , wherein the metallic thin film has vertical magnetic anisotropy which is a magnetic anisotropy in a normal direction of the thin film.  
     
     
         3 . A magneto-optical recording medium according to  claim 1 , wherein the metallic thin film has magneto-optical effect which is a polar Kerr rotation angle and/or Kerr ellipticity which are/is 0.1° or over with respect to ultraviolet light having a wavelength of 200 nm or less.  
     
     
         4 . A magneto-optical recording medium according to  claim 1 , wherein the metallic thin film has a negative Kerr rotation angle in most of a visible light region, and a positive polar Kerr rotation angle of 0.1° or over in a visible light region with a short wavelength or an ultraviolet region.  
     
     
         5 . A magneto-optical recording medium for recording information by utilizing magneto-optical effects of a metallic thin film; 
 the magneto thin film comprising Co,    the magneto-optical effects being a polar Kerr rotation angle and/or Kerr ellipticity which have/has an absolute value of 0.1° or over with respect to ultraviolet light having a wavelength of 400 nm or less,    the metallic thin film being a multi-layered film including a Co crystalline thin film and a crystalline thin film with R components, R may be at least any one of transition metals, rare-earth elements, Pt, Ta, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Au, and W.    
     
     
         6 . A magneto-optical recording medium according to  claim 5 , wherein the metallic thin film has magneto-optical effect which is a polar Kerr rotation angle and/or Kerr ellipticity which are/is 0.1° or over with respect to ultraviolet light having a wavelength of 200 nm or less.  
     
     
         7 . A magneto-optical recording medium according to  claim 5 , wherein the metallic thin film has a negative Kerr rotation angle in most of a visible light region, and a positive polar Kerr rotation angle of 0.1° or over in a visible light region with a short wavelength or an ultraviolet region.  
     
     
         8 . A magneto-optical recording device using a magneto-optical recording medium for recording information by utilizing magneto-optical effects of a metallic thin film; 
 the magneto thin film comprising Co,    the magneto-optical effects being a polar Kerr rotation angle and/or Kerr ellipticity which have/has an absolute value of 0.1° or over with respect to ultraviolet light having a wavelength of 400 nm or less,    the magneto-optical recording device comprising 
 irradiation means for irradiating ultraviolet light having a wavelength of 400 nm or less onto a magneto-optical recording medium, and  
 a vessel for enclosing the magneto-optical recording medium in an atmosphere with a small absorption rate of ultraviolet light.  
   
     
     
         9 . A device according to  claim 8 , wherein 
 the irradiation means includes frequency doubling means for converting light supplied from a light source into light having a half wavelength by means of frequency doubling, and    the magneto-optical recording means is irradiated by light from a light source after halving the wavelength thereof.