Nano-crystalline, magnetic alloy, its production method, alloy ribbon and magnetic part

1. A magnetic alloy having a composition represented by the following general formula (1):

Fe 100-x-y Cu x B y (atomic %)  (1),

wherein x and y are numbers meeting the conditions of 1.2≦x≦1.6, and 10≦y≦20, wherein said magnetic alloy has a structure containing crystal grains having an average diameter of 60 nm or less which is dispersed in a proportion of 30% or more by volume in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more and a coercivity of 24 A/m or less, and wherein said magnetic alloy is obtained by heat-treating a fine crystalline alloy having a structure in which crystal grains having an average diameter of 30 nm or less are dispersed in an amorphous phase in a proportion of more than 0% by volume and 30% by volume or less.

2. The magnetic alloy according to claim 1 , which has maximum permeability of 20,000 or more.

3. The magnetic alloy according to claim 1 , wherein a part of Fe is substituted by Ni and/or Co in a proportion of 10 atomic % or less based on Fe.

4. The magnetic alloy according to claim 1 , wherein a part of Fe is substituted by at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, platinum-group elements, Au, Ag, Zn, In, Sn, As, Sb, Bi, Y, N, 0 and rare earth elements in a proportion of 5 atomic % or less based on Fe.

5. The magnetic alloy according to claim 1 , which is in a powder or flake shape.

6. A magnetic alloy having a composition represented by the following general formula (2):

Fe 100-x-y-z Cu x B y X z (atomic %)  (2),

wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 1.2≦x≦1.6, 12≦y≦17, 0<z≦7, and 13<y+z≦20, wherein said magnetic alloy has a structure containing crystal grains having an average diameter of 60 nm or less which is dispersed in a proportion of 30% or more by volume in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more and a coercivity of 24 A/m or less, and wherein said magnetic alloy is obtained by heat-treating a fine crystalline alloy having a structure in which crystal grains having an average diameter of 30 nm or less are dispersed in an amorphous phase in a proportion of more than 0% by volume and 30% by volume or less.

7. The magnetic alloy according to claim 6 , wherein said X is Si and/or P.

8. The magnetic alloy according to claim 6 , which has maximum permeability of 20,000 or more.

9. The magnetic alloy according to claim 6 , wherein a part of Fe is substituted by Ni and/or Co in a proportion of 10 atomic % or less based on Fe.

10. The magnetic alloy according to claim 6 , wherein a part of Fe is substituted by at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, platinum-group elements, Au, Ag, Zn, In, Sn, As, Sb, Bi, Y, N, 0 and rare earth elements in a proportion of 5 atomic % or less based on Fe.

11. The magnetic alloy according to claim 6 , which is in a powder or flake shape.

12. A magnetic part made of the magnetic alloy according to claim 1 .

13. A magnetic part made of the magnetic alloy according to claim 6 .

14. The magnetic alloy according to claim 1 , wherein a part of Fe is substituted by Ni and/or Co in a proportion of 10 atomic % or less based on Fe, and at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, platinum-group elements, Au, Ag, Zn, In, Sn, As, Sb, Bi, Y, N, O and rare earth elements in a proportion of 5 atomic % or less based on Fe.

15. The magnetic alloy according to claim 1 , wherein 1.2≦x≦1.6 and 12≦y≦17.

16. The magnetic alloy according to claim 1 , wherein 1.2≦x≦1.6 and 12≦y≦15.

17. The magnetic alloy according to claim 1 , wherein an average diameter of the crystal grains in the fine crystalline alloy is 0.5 nm to 20 nm.

18. The magnetic alloy according to claim 1 , wherein an average distance between the crystal grains in the fine crystalline alloy is 50 nm or less.

19. The magnetic alloy according to claim 6 , wherein a part of Fe is substituted by Ni and/or Co in a proportion of 10 atomic % or less based on Fe, and at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, platinum-group elements, Au, Ag, Zn, In, Sn, As, Sb, Bi, Y, N, O and rare earth elements in a proportion of 5 atomic % or less based on Fe.

20. The magnetic alloy according to claim 6 , wherein 1.2≦x≦1.6, 12≦y≦15, 0<z≦5, and 14≦y+z≦19.

21. The magnetic alloy according to claim 6 , wherein 1.2≦x≦1.6, 12≦y≦15, 0<z≦4, and 14≦y+z≦17.

22. The magnetic alloy according to claim 6 , wherein an average diameter of the crystal grains in the fine crystalline alloy is 0.5 nm to 20 nm.

23. The magnetic alloy according to claim 6 , wherein an average distance between the crystal grains in the fine crystalline alloy is 50 nm or less.

24. The magnetic alloy according to claim 1 , wherein said magnetic alloy is obtained by heat-treating a fine crystalline alloy having a structure in which crystal grains having an average diameter of 30 nm or less are dispersed in an amorphous phase in a proportion of more than 3% by volume and 30% by volume or less.

25. The magnetic alloy according to claim 1 , wherein said magnetic alloy has a coercivity of 12 A/m or less.

26. The magnetic alloy according to claim 6 , wherein said magnetic alloy is obtained by heat-treating a fine crystalline alloy having a structure in which crystal grains having an average diameter of 30 nm or less are dispersed in an amorphous phase in a proportion of more than 3% by volume and 30% by volume or less.

27. The magnetic alloy according to claim 6 , wherein said magnetic alloy has a coercivity of 12 A/m or less.