Analysis of Cubic Boron Nitride Single Crystal Defects Growth under High Temperature and High Pressure

Abstract

Cubic boron nitride (cBN) single crystals are synthesized under high temperature and high pressure in the Li-based system. The growth defects on hexagonal and triangular (111) surfaces of cBN single crystals after rapid cooling are discussed systemically for the first time using the atomic force microscope. Some impurity particles, triangle cone hole defects, lamellar-fault structures, and big steps are obvious on the surfaces of cBN single crystals. The formation mechanism of these defects is analyzed briefly at the synthetic process of cBN single crystals, and the growth mechanism of cBN single crystals transform from the two-dimensional growth to dislocation growth mechanism under high temperature and high pressure.

First-principles study on structural, mechanical, electrical, optical and thermal properties of lithium- and calcium-based catalysts

“…At present, the catalysts used in industrial synthesis are mainly nitrides or nitride borides of alkali metals and alkaline earth metals. Many scholars have shown that alkali earth metal nitrides will produce corresponding boron nitrides at high temperatures and pressures [8][9][10]. For example, in the synthetic system where Li 3 N and Ca 3 N 2 are catalysts, the corresponding metal boron nitrides Li 3 BN 2 and Ca 3 B 2 N will be generated.…”

“…For example, in the synthetic system where Li 3 N and Ca 3 N 2 are catalysts, the corresponding metal boron nitrides Li 3 BN 2 and Ca 3 B 2 N will be generated. Many studies have shown that the real catalyst for c-BN synthesis in an alkali metal or alkaline earth metal system at high temperature and pressure is ternary alkali metal or alkaline earth metal boron nitride [8,9]. E. Tadashi of the National Institute of Inorganic Materials in Japan proposed that high purity ternary compound catalysts must be used to synthesize high-grade c-BN.…”