Compositionally modulated, nitrided alloy films and method for making the same

A compositionally modulated, nitrided magnetic alloy film consisting essentially of an alloy having an average composition of the following formula

• Fe.sub.x Si.sub.y N.sub.z T'.sub.w
• in which T' represents at least one member selected from the group consisting of Nb, Ta, Ti, Zr, Hf, Cr, Mo and W, and 70.ltoreq.x.ltoreq.97, 1.ltoreq.y.ltoreq.20, 1.ltoreq.z.ltoreq.15 and 1.ltoreq.w.ltoreq.10, each on the atomic percent basis, provided that x+y+z+w=100, at least the content of the nitrogen along the thickness of the film being compositionally modulated.

A compositionally modulated, nitrided magnetic alloy film consisting essentially of an alloy having an average composition of the following formula

• (Fe.sub.a Si.sub.b' Ru.sub.c')(100-.sub.d)/100N.sub.d'
• in which 70.ltoreq.a'.ltoreq.96, 3.ltoreq.b'.ltoreq.20, 1.ltoreq.c'.ltoreq.6 and 1.ltoreq.d'.ltoreq.15, each on the atomic percent basis, provided that a'+b'+c'+d'=100, and the content of the nitrogen along the thickness of the film being compositionally modulated.

A method for making a compositionally modulated, nitrided magnetic alloy film having an average composition of T.sub.a X.sub.b N.sub.c wherein T represents at least one member selected from the group consisting of Fe, Fe and Co, and Fe and Ni, X represents at least one member selected from the group consisting of Si, Ge, Si and Ga, and Ge and Al, and N is nitrogen 71.ltoreq.a.ltoreq.97, 2.ltoreq.b.ltoreq.28 and 1.ltoreq.c.ltoreq.20, each based on the atomic percent basis, provided that a+b+c=100, at least the nitrogen being compositionally modulated along the thickness of the film, the method comprising providing a target of a nitride-free Fe based alloy, and subjecting said target to sputtering first in an Ar gas atmosphere for a time sufficient to form a nitride-free Fe based alloy layer on a substrate and then in the Ar gas atmosphere to which nitrogen gas is added to a level of from 0.1 to 50% by partial pressure, so that a nitride alloy layer is formed on the nitride-free Fe based alloy layer.

A method for making a compositionally modulated, nitride magnetic alloy film having an average composition of Fe.sub.x Si.sub.y N.sub.z T'.sub.w

• wherein T' represents at least one member selected from the group consisting of Nb, Ta, Ti, Zr, Hf, Cr, Mo and W, and 70.ltoreq.x.ltoreq.97, 1.ltoreq.y.ltoreq.20, 1.ltoreq.z.ltoreq.15 and 1.ltoreq.w.ltoreq.10, each based on the atomic percent basis, provided that x+y+z+w=100, at least the nitrogen being compositionally modulated along the thickness of the film, the method comprising providing a target of a nitride-free Fe based alloy, and subjecting said target to sputtering first in an Ar gas atmoshpere for a time sufficient to form a nitride-free Fe based alloy layer on a substrate and then in the Ar gas atmosphere to which nitrogen gas is added to a level of from 0.1 to 50% by partial pressure, so that a nitride alloy layer is formed on the nitride-free Fe based alloy layer.

A method for making a compositionally modulated, nitride magnetic alloy film having an average composition

• Fe.sub.a' Si.sub.b' Ru.sub.c')(100-.sub.d')/'100N.sub.d'
• wherein 70.ltoreq.a.ltoreq.96, 3.ltoreq.b'.ltoreq.20, 1.ltoreq.c'.ltoreq.6 and 1.ltoreq.d'.ltoreq.15, each based on the atomic percent basis, provided that a'+b'+c'+d'=100, at least the nitrogen being compositionally modulated along the thickness of the film, the method comprising providing a target of a nitride-free Fe based alloy, and subjecting said target to sputtering first in an Ar gas atmosphere for a time sufficient to form a nitride-free Fe based alloy layer on a substrate and then in the Ar gas atmosphere to which nitrogen gas is added to a level of from 0.1 to 50% by partial pressure, so that a nitride alloy layer is formed on the nitride-free Fe based alloy layer.