POLYCRYSTALLINE CUBIC BORON NITRIDE AND PRODUCTION METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide polycrystalline cubic boron nitride in which conductivity is imparted while reduction in mechanical strength is suppressed.SOLUTION: The polycrystalline cubic boron nitride comprises nitrogen, boron, and a heterogeneous element introduced as a dopant into a crystalline structure composed of nitrogen and boron. The heterogeneous element comprises one or more elements selected from a group consisting of group-1 elements and group-2 elements, or one or more elements selected from a group consisting of group-14 elements and group-16 elements excluding oxygen. A content percentage of the heterogeneous element stepwisely or continuously varies in a thickness direction of the polycrystalline cubic boron nitride.