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

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

• Fe100-x-yCuxBy(atomic %) (1),
• wherein x and y are numbers meeting the conditions of 0.1≦x≦3, and 10≦y≦20, said magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.

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

• Fe100-x-y-zCuxByXz(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 0.1≦x≦3, 10≦y≦20, 0≦z≦10, and 10<y+z≦24, said magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.

An alloy ribbon having a composition represented by the following general formula (1):

• Fe100-x-yCuxBy(atomic %) (1),
• wherein x and y are numbers meeting the conditions of 0.1≦x≦3, and 10≦y≦20, said alloy ribbon having a structure containing fine crystal grains having an average diameter of 30 nm or less in an amorphous matrix.

An alloy ribbon having a composition represented by the following general formula (2):

• Fe100-x-y-zCuxByXz(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 0.1≦x≦3, 10≦y≦20, 0≦z≦10, and 10<y+z≦24, said alloy ribbon having a structure containing fine crystal grains having an average diameter of 30 nm or less in an amorphous matrix.

A method for producing a magnetic alloy, comprising the steps of quenching an alloy melt comprising Fe and a metalloid element to produce a Fe-based alloy having a structure in which crystal grains having an average diameter of 30 nm or less are dispersed in an amorphous matrix in a proportion of more than 0% by volume and 30% by volume or less, and heat-treating said Fe-based alloy to have a structure in which body-centered-cubic crystal grains having an average diameter of 60 nm or less are dispersed in an amorphous matrix in a proportion of 30% or more by volume.