Effective cooling of substrates with low thermal conductivity under conditions of gas-jet MPCVD diamond synthesis

The paper presents the results of an experimental study of heating molybdenum and silicon substrates under the conditions of gas-jet deposition of diamond structures using the precursor gases of a microwave discharge to activate. A cooled substrate holder using a metal melt to improve heat removal by reducing the thermal resistance between the substrate and the substrate holder has been developed. The use of the melt allowed lowering the temperature of the silicon substrate under the conditions of gas-jet deposition to a level that ensures the preservation of its structure. The developed substrate holders were used to carry out gas-jet synthesis of diamond structures on molybdenum and silicon substrates.

Effect of Ni2O3 on diamond crystal growth in an Fe–Ni–C system under high temperature and high pressure

In this paper, the oxygen-containing diamond large single crystals were successfully synthesized by adding Ni2O3 to the Fe–Ni–C system under HPHT. The oxygen affects the P–T conditions for diamond synthesis, and morphology of diamond.

Growth and characterization of diamond single crystals grown in the Fe–S–C system by the temperature gradient method

Diagram of the apparatus for the HPHT diamond synthesis: (a) alloy hammer + pyrophyllite assembly block; (b) sample assembly.

The Transformation from (111) to (100): A Routine to Large-Scale Epitaxial Diamond

Diamond is a material with excellent performances which attracts the attention from researchers for decades. Pt (111), owing to its catalytic activity on diamond synthesis, is regarded to be a candidate for diamond hetero-epitaxity, which can enhance nucleation density. Molten surface at diamond growth temperature can also improve mobility and aggregation capability of primitive nuclei. Generally, (100)-oriented is welcomed for the achivement of high quality and large size diamond, since the formation of defects and twins are prevented. First-principle calculations and experimental researches were carried out for the study of transformation of orientation. The transformation from {111} to {100}-oriented diamond has been observed on Pt (111) substrate, which can be promoted by the increase of carbon source concentration and substrate temperature. The process is energetic favorable, which may provides a way towards large-scale (100) diamond films.