FePt-C-BASED SPUTTERING TARGET

An FePt—C-based sputtering target containing Fe, Pt, and C and further containing at least one element other than Fe and Pt, wherein

• the FePt—C-based sputtering target has a structure in which a C phase substantially being C is dispersed in an FePt-based alloy phase containing 33 mol % or more and less than 60 mol % of Pt and more than 0 mol % and 20 mol % or less of the at least one element other than Fe and Pt with the balance substantially being Fe and with the total amount of Pt and the at least one element being 60 mol % or less, and
• when in each of 10 images taken at 10 locations in a cross section of the FePt—C-based sputtering target in a thickness direction thereof with a field of view having a size of 121 μm×97 μm taken with 1,000× magnification, an average value of diameters of five inscribed circles from a largest diameter to a fifth largest diameter of inscribed circles of the C phase is regarded as a size index a of the C phase, and a value L/R for each C phase from the largest diameter to the fifth largest diameter of the inscribed circles is determined by dividing a maximum length L of a straight line among straight lines connecting a center of each of the five inscribed circles of the C phase from the largest diameter to the fifth largest diameter to an interface of the C phase by a radius R of the inscribed circle associated with the maximum length L, and an average value of the resulting five values L/R is regarded as a nonspherical index b of the C phase, an average value of the size indices a of the C phase obtained for the respective 10 images is 4.0 μm or more and 9.0 μm or less, and an average value of the nonspherical indices b of the C phase determined for the respective 10 images is 3.0 or more.

An FePt—C-based sputtering target containing Fe, Pt, C, and oxide, wherein

• the FePt—C-based sputtering target has a structure in which a C phase substantially being C and an oxide phase substantially being oxide are dispersed in an FePt-based alloy phase containing 33 mol % or more and 60 mol % or less of Pt with the balance substantially being Fe, and
• when in each of 10 images taken at 10 locations in a cross section of the FePt—C-based sputtering target in a thickness direction thereof with a field of view having a size of 121 μm×97 μm taken with 1,000× magnification, an average value of diameters of five inscribed circles from a largest diameter to a fifth largest diameter of inscribed circles of the C phase is regarded as a size index a of the C phase, and a value L/R for each C phase from the largest diameter to the fifth largest diameter of the inscribed circles is determined by dividing a maximum length L of a straight line among straight lines connecting a center of each of the five inscribed circles of the C phase from the largest diameter to the fifth largest diameter to an interface of the C phase by a radius R of the inscribed circle associated with the maximum length L, and an average value of the resulting five values L/R is regarded as a nonspherical index b of the C phase, an average value of the size indices a of the C phase obtained for the respective 10 images is 4.0 μm or more and 9.0 μm or less, and an average value of the nonspherical indices b of the C phase determined for the respective 10 images is 3.0 or more.

An FePt—C-based sputtering target containing Fe, Pt, C, and oxide and further containing at least one element other than Fe and Pt, wherein

• the FePt—C-based sputtering target has a structure in which a C phase substantially being C and an oxide phase substantially being oxide are dispersed in an FePt-based alloy phase containing 33 mol % or more and less than 60 mol % of Pt and more than 0 mol % and 20 mol % or less of the at least one element other than Fe and Pt with the balance being Fe and unavoidable impurities and with the total amount of Pt and the at least one element being 60 mol % or less, and
• when in each of 10 images taken at 10 locations in a cross section of the FePt—C-based sputtering target in a thickness direction thereof with a field of view having a size of 121 μm×97 μm taken with 1,000× magnification, an average value of diameters of five inscribed circles from a largest diameter to a fifth largest diameter of inscribed circles of the C phase is regarded as a size index a of the C phase, and a value L/R for each C phase from the largest diameter to the fifth largest diameter of the inscribed circles is determined by dividing a maximum length L of a straight line among straight lines connecting a center of each of the five inscribed circles of the C phase from the largest diameter to the fifth largest diameter to an interface of the C phase by a radius R of the inscribed circle associated with the maximum length L, and an average value of the resulting five values L/R is regarded as a nonspherical index b of the C phase, an average value of the size indices a of the C phase obtained for the respective 10 images is 4.0 μm or more and 9.0 μm or less, and an average value of the nonspherical indices b of the C phase determined for the respective 10 images is 3.0 or more.