Magneto-optical recording medium having a plurality of ferromagnetic thin layers

Abstract

A magneto-optical device including a substrate which is transparent to light in a visible spectrum region and, a plurality of ferromagnetic layers arranged thereon, each ferromagnetic layer preferably having a width ranging from in an inclusive range of 5 to through 100 nanometers and a thickness ranging from in an inclusive range of 0.1 to through 5 microns. The, wherein said ferromagnetic layers are parallel to each other and separated by a distance ranging from in an inclusive range of 0.2 to through 2 microns. The ferromagnetic layers are arranged preferably on the side walls of grooves formed parallel to each other in the transparent substrate.

1. A magneto-optical device comprising:
 a substrate transparent to light in a visible spectral region; 
 a plurality of ferromagnetic layers having a width in an inclusive range of 5 through 100 nanometers and a thickness in an inclusive range of 0.1 through 5 microns; 
 wherein said ferromagnetic layers are parallel to each other and separated by a distance in an inclusive range of 0.2 through 2 microns. 
 
     
     
       2. The magneto-optical device of  claim 1 , wherein said substrate defines grooves having side walls, said ferromagnetic layers being arranged on said side walls. 
     
     
       3. The magneto-optical device of  claim 2 , wherein said side walls are perpendicular to a surface of said substrate. 
     
     
       4. The magneto-optical device of  claim 1 , further comprising a reflecting layer on a first face of said substrate. 
     
     
       5. The magneto-optical device of  claim 4 , further comprising an anti-reflecting layer on a second face of said substrate. 
     
     
       6. The magneto-optical device of  claim 1 , wherein said ferromagnetic layers are electrically conductive. 
     
     
       7. The magneto-optical device of  claim 6 , wherein said ferromagnetic layers comprise particles of a member of the group consisting of Fe, Co, Ni, FeCo alloys, FeNi alloys and CoNi alloys. 
     
     
       8. The magneto-optical device of  claim 7 , wherein said ferromagnetic layers particles have an average diameter in an inclusive range of 2 through 20 nanometers. 
     
     
       9. The magneto-optical device of  claim 1 , further comprising a layer of non-magnetic semiconducting material or metal in contact with said ferromagnetic layers and having a same thickness as the thickness of the ferromagnetic layers and a width in an inclusive range of 5 through 10 nanometers. 
     
     
       10. The magneto-optical device of  claim 2 , further comprising a reflecting layer on a first face of said substrate. 
     
     
       11. The magneto-optical device of  claim 10 , further comprising an anti-reflecting layer on a second face of said substrate. 
     
     
       12. The magneto-optical device of  claim 2 , wherein said ferromagnetic layers are electrically conductive. 
     
     
       13. The magneto-optical device of  claim 12 , wherein said ferromagnetic layers comprise particles of a member of the group consisting of Fe, Co, Ni, FeCo alloys, FeNi alloys and CoNi alloys. 
     
     
       14. The magneto-optical device of  claim 13 , wherein said ferromagnetic layers particles have an average diameter in an inclusive range of 2 through 20 nanometers. 
     
     
       15. The magneto-optical device of  claim 2 , further comprising a layer of non-magnetic semiconducting material or metal in contact with said ferromagnetic layers and having a same thickness as the thickness of the ferromagnetic layers and a width in an inclusive range of 5 through 10 nanometers. 
     
     
       16. The magneto-optical device of  claim 3 , further comprising a reflecting layer on a first face of said substrate. 
     
     
       17. The magneto-optical device of  claim 16 , further comprising an anti-reflecting layer on a second face of said substrate. 
     
     
       18. The magneto-optical device of  claim 3 , wherein said ferromagnetic layers are electrically conductive. 
     
     
       19. The magneto-optical device of  claim 18 , wherein said ferromagnetic layers comprise particles of a member of the group consisting of Fe, Co, Ni, FeCo alloys, FeNi alloys and CoNi alloys. 
     
     
       20. The magneto-optical device of  claim 19 , wherein said ferromagnetic layers particles have an average diameter in an inclusive range of 2 through 20 nanometers. 
     
     
       21. The magneto-optical device of  claim 3 , further comprising a layer of non-magnetic semiconducting material or metal in contact with said ferromagnetic layers and having a same thickness as the thickness of the ferromagnetic layers and a width in an inclusive range of 5 through 10 nanometers. 
     
     
       22. A magneto-optical device comprising:
 a substrate transparent to light in a visible spectral region; and   a plurality of ferromagnetic layers having a width in an inclusive range of 5 through 100 nanometers and a thickness in an inclusive range of 0.1 through 5 microns;   wherein said ferromagnetic layers are parallel to each other.   
     
     
       23. The magneto-optical device of claim 22, wherein said substrate defines grooves having side walls, said ferromagnetic layers being arranged on said side walls. 
     
     
       24. The magneto-optical device of claim 23, wherein said side walls are perpendicular to a surface of said substrate. 
     
     
       25. The magneto-optical device of claim 22, further comprising a reflecting layer on a first face of said substrate. 
     
     
       26. The magneto-optical device of claim 25, further comprising an anti-reflecting layer on a second face of said substrate. 
     
     
       27. The magneto-optical device of claim 22, wherein said ferromagnetic layers are electrically conductive. 
     
     
       28. The magneto-optical device of claim 27, wherein said ferromagnetic layers comprise particles of a member of the group consisting of Fe, Co, Ni, FeCo alloys, FeNi alloys and CoNi alloys. 
     
     
       29. A recording device comprising:
 a magneto-optical device comprising:
 a substrate, and 
 a plurality of ferromagnetic layers on said substrate; and 
   a magnetic recording head, on which said magneto-optical device is positioned,   wherein said magnetic recording head comprises a plurality of bars of magnetic material.   
     
     
       30. The recording device of claim 29, wherein said magnetic recording head further comprises lines wound around said bars of magnetic material. 
     
     
       31. The recording device of claim 30, wherein said bars of magnetic material are arranged in a matrix. 
     
     
       32. An image forming apparatus comprising:
 an array of magnetic heads; and   a magneto-optical device on said array and comprising:
 a substrate, and 
 a plurality of ferromagnetic layers formed on said substrate, 
   wherein a relative position between the magneto-optical device and the magnetic heads does not change during a recording operation.   
     
     
       33. The image forming apparatus of claim 32, wherein said ferromagnetic layers have a width in an inclusive range of 5 through 100 nanometers. 
     
     
       34. The image forming apparatus of claim 32, wherein said ferromagnetic layers have a thickness in an inclusive range of 0.1 through 5 microns. 
     
     
       35. The image forming apparatus of claim 32, wherein said ferromagnetic layers are parallel to each other. 
     
     
       36. The image forming apparatus of claim 35, wherein said ferromagnetic layers are separated by a distance in an inclusive range of 0.2 through 2 microns. 
     
     
       37. The image forming apparatus of claim 32, wherein said substrate defines grooves having side walls, said ferromagnetic layers being arranged on said side walls. 
     
     
       38. The image forming apparatus of claim 37, wherein said side walls are perpendicular to a surface of said substrate. 
     
     
       39. The image forming apparatus of claim 32, wherein said ferromagnetic layers are formed by a method selected from the group consisting of sputtering, PVD, CVD and plating. 
     
     
       40. The image forming apparatus of claim 32, further comprising:
 an address circuit configured to select a line of said array of magnetic heads; and   a driver circuit configured to input and erase information data to each head on the selected line.   
     
     
       41. The image forming apparatus of claim 40, further comprising a controller configured to control writing and erasing operations of said information data. 
     
     
       42. The magneto-optical device of claim 32, wherein each magnetic head of said array of magnetic heads includes a micro magnetic head and a reading head. 
     
     
       43. The image forming apparatus of claim 42, wherein said reading head comprises a magnetoresistance film. 
     
     
       44. The recording device of claim 41, wherein each of said ferromagnetic layers is positioned on a wall of said grooves. 
     
     
       45. The recording device of claim 44, wherein said ferromagnetic layers are separated from each other. 
     
     
       46. The recording device of claim 45, wherein said ferromagnetic layers are parallel to each other.