Sputtering Target, Method for Producing Laminated Film, Laminated Film and Magnetic Recording Medium

1 . A sputtering target containing Co and one or more metals selected from the group consisting of Cr and Ru, as metal components, wherein a molar ratio of the content of the one or more metals selected from the group consisting of Cr and Ru to the content of Co is ½ or more, and wherein the sputtering target contains Nb 2 O 5 as a metal oxide component.

2 . The sputtering target according to claim 1 , wherein the sputtering target contains only Nb 2 O 5 as a metal oxide component, and wherein the sputtering target has a content of Nb 2 O 5 of from 5 mol % to 15 mol %.

3 . The sputtering target according to claim 1 , wherein the sputtering target has a content of Nb 2 O 5 of from 2 mol % to 5 mol % and further comprises at least one metal oxide other than Nb 2 O 5 , and wherein the sputtering target has a total content of metal oxides including Nb 2 O 5 of 30 vol % or more.

4 . The sputtering target according to claim 3 , wherein the at least one metal oxide other than the Nb 2 O 5 is at least one metal oxide selected from the group consisting of TiO 2 , SiO 2 , B 2 O 3 , CoO, Co 3 O 4 , Cr 2 O 3 , Ta 2 O 5 , ZnO, and MnO.

5 . The sputtering target according to claim 1 , wherein the sputtering target contains Co in an amount of from 15 mol % to 60 mol %.

6 . The sputtering target according to claim 1 , wherein the sputtering target contains Cr and/or Ru, and wherein a total content of Cr and Ru is from 30 mol % to 60 mol %.

7 . The sputtering target according to claim 1 , wherein the sputtering target further contains Pt in an amount of from 5 mol % to 30 mol % as a metal component.

8 . A method for producing a laminated film, comprising forming an intermediate layer on a base layer containing Ru by sputtering using the sputtering target according to claim 1 .

9 . The method for producing the laminated film according to claim 8 , further comprising forming a magnetic layer on the intermediate layer by sputtering using a sputtering target containing Co and Pt as metal components.

10 . A laminated film, comprising: a base layer containing Ru; and an intermediate layer formed on the base layer, the intermediate layer containing Co and one or more metals selected from the group consisting of Cr and Ru as metal components, the intermediate layer having a molar ratio of the content of the one or more metals selected from the group consisting of Ru and Co to the content of Co of ½ or more; and a magnetic layer formed on the intermediate layer, the magnetic layer containing Co and Pt as metal components, wherein the intermediate layer contains Nb 2 O 5 as a metal oxide component.

11 . A magnetic recording medium comprising the laminated film according to claim 10 .