Sputtering target of nonmagnetic-particle-dispersed ferromagnetic material
View Patent ↗Provided is a sputtering target of nonmagnetic-particle-dispersed ferromagnetic material comprising a phase (A) such that nonmagnetic particles are dispersed in a ferromagnetic material formed from a Co—Cr alloy containing 5 at % or more and 20 at % or less of Cr and Co as the remainder thereof, and schistose textures (B) with a short side of 30 to 100 μm and a long side of 50 to 300 μm formed from a Co—Cr alloy phase in the phase (A); wherein each of the foregoing nonmagnetic particles has such a shape and size that the particle is smaller than all hypothetical circles with a radius of 1 μm around an arbitrary point within the nonmagnetic particle, or a shape and size with at least two contact points or intersection points between the respective hypothetical circles and the interface of the ferromagnetic material and the nonmagnetic material.
1. A sintered sputtering target comprising a ferromagnetic alloy dispersed with nonmagnetic oxide particles characterized in that:
the ferromagnetic alloy contains a composition consisting essentially of 5-20 at % Cr, 5-30 at % Pt, and Co as remainder;
the sintered sputtering target has a structure comprising a ferromagnetic alloy phase (A) in which the nonmagnetic oxide particles and particles of a Co—Cr—Pt alloy phase (B) are dispersed, the particles of the Co—Cr—Pt alloy phase (B) having a schistose shape with a short side length of 30 to 100 μm and a long side length of 50 to 300 μm; and
Cr is concentrated to 25 at % or more at a central part of each of the particles of the Co—Cr—Pt alloy phase (B) and is lower in concentration at a periphery of each of the particles of the Co—Cr—Pt alloy phase (B).
2. The sputtering target according to claim 1 , wherein, in any cross-section extending through the sputtering target, the Co—Cr—Pt alloy phase (B) has an area ratio of 4% or more and 30% or less relative to an overall area of the cross-section including the phase (A) in which the nonmagnetic oxide particles are dispersed.
3. The sputtering target according to claim 1 , wherein the nonmagnetic oxide particles are one or more oxides selected from the group consisting of Cr, Ta, Si, Ti, Zr, Al, Nb and B oxides.
4. The sputtering target according to claim 3 , wherein the nonmagnetic oxide particles have a volume ratio of 10% or more and 30% or less relative to a total volume of the sputtering target.
5. The sputtering target according to claim 1 , wherein the sputtering target has a relative density of 97% or higher.
6. The sintered sputtering target according to claim 1 , wherein the Co—Cr—Pt alloy phase (B) particles having the schistose shape are in the form of particle flakes.
7. A sputtering target, comprising a sintered body of a mixture of nonmagnetic oxide particles and a ferromagnetic alloy consisting of 5 to 20 at % Cr, 5 to 30 at % Pt, and remainder Co, the nonmagnetic oxide particles and schistose Co—Cr—Pt alloy particles being dispersed within a matrix of the ferromagnetic alloy of the sintered body, the schistose Co—Cr—Pt alloy particles each having a short side length dimension of 30 to 100 μm and a long side length dimension of 50 to 300 μm, and Cr being concentrated to 25 at % or more at a central part of each of the schistose Co—Cr—Pt alloy particles and is lower in concentration at a periphery of each of the schistose Co—Cr—Pt alloy particles.
8. The sputtering target according to claim 7 , wherein, in any cross-section extending through the sputtering target, the schistose Co—Cr—Pt alloy particles have an area ratio of 4 to 30% relative to an overall area of the cross-section.
9. The sputtering target according to claim 8 , wherein the nonmagnetic oxide particles have a volume ratio of 10 to 30% relative to a total volume of the sputtering target.
10. The sputtering target according to claim 9 , wherein the nonmagnetic oxide particles are oxide particles selected from the group consisting of Cr, Ta, Si, Ti, Zr, Al, Nb and B oxide particles.
11. The sputtering target according to claim 10 , wherein the sputtering target has a relative density of 97% or higher.