POLYCRYSTALLINE DIAMOND, MANUFACTURING METHOD THEREFOR, SCRIBE TOOL, SCRIBE WHEEL, DRESSER, ROTARY TOOL, WATER-JET ORIFICE, WIRE DRAWING DIE, CUTTING TOOL, AND ELECTRON SOURCE

摘要

Polycrystalline diamond, comprising: carbon; a group III element and/or a group V element added to be dispersed in said carbon at an atomic level; and an inevitable impurity, the polycrystalline diamond having a crystal grain size not greater than 500 nm.