▎ 摘　　要

NOVELTY - An sp2-sp3 hybrid crystalline boron nitride has basic structural unit composed of sp2 hybridized graphite-like structural unit and sp3 hybridized diamond-like structural unit, where the two types of units are connected via a coherent interface. USE - An sp2-sp3 hybrid crystalline boron nitride. ADVANTAGE - The sp2-sp3 hybrid crystalline boron nitride, i.e. Gradia BN, has a density lower than cBN. As a result, the volume shrinkage during the high-pressure phase transition process is relatively small, which is beneficial for the formation of a block material with good formability. The high-temperature high-pressure equipment used in the method is currently widely used, and has the advantages of simplicity of operation and ease of controlling synthesis parameters. At the same time, the raw materials used are abundant and inexpensive. Thus, the Gradia BN may be produced in an industrial scale, and their crystal structures can be adjusted to achieve regulation of performances. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of sp2-sp3 hybrid crystalline boron nitride which involves subjecting a boron nitride material to high-temperature and high-pressure treatment.