Sputtering target of nonmagnetic-particle-dispersed ferromagnetic material
View Patent ↗A sputtering target of nonmagnetic-particle-dispersed ferromagnetic material is provided having 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, 0.5-8 at % B, 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—B alloy phase (B) are dispersed, the particles of the Co—Cr—Pt—B 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—B alloy phase (B) and is lower in concentration at a periphery of each of the particles of the Co—Cr—Pt—B 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—B 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 of nonmagnetic-particle-dispersed ferromagnetic material according to claim 1 , wherein the nonmagnetic material is one or more types of oxides selected from Cr, Ta, Si, Ti, Zr, Al, Nb and B.
4. The sputtering target according to claim 1 , 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 of nonmagnetic-particle-dispersed ferromagnetic material according to claim 1 , wherein a relative density of the sputtering target is 97% or higher.