Investigation of sulphur additions on kinetic processes of cubic boron nitride crystallization in the LiBNH system

Gameza, L. M.; Shipilo, V. B.; Savchuk, V. A.

doi:10.1016/s0925-9635(97)00157-x

Cited by 4 publications

(2 citation statements)

References 2 publications

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“…YO) was introduced into graphite-like boron nitride (hBN) as the catalyst-solvent, which was carefully mixed with easily decomposable additions containing hydrogen-and nitrogen (8.0wt.Yo) and 0.25 and 0.50 wt.% beryllium, respectively. As evidenced by our early investigations [3,4] concerning the influence of doping additions of Se and S (up to 7.0 wt.%) on the crystallization processes in the BN-Li3N system, the amount of beryllium in the mixture should not be too high since it suppresses the nucleation and growth of cBN single crystals. In this case, the degree of conversion does not exceed 0.05 and therefore the concentration of the doping addition in the experiments was not higher than 0.50wt.%.…”

Section: Methodsmentioning

confidence: 83%

Peculiarities of spontaneous crystallization of cubic boron nitride single crystal powders in the Li-B-N (H, Be) system

Gameza

2000

High Pressure Research

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We have investigated the effect of beryllium additions on the kinetics of conversion of hexagonal graphite-like BN to cubic BN (hBN -+ cBN) as well as on the linear rate of cBN crystal growth in a Li-B-N (H, Be) system. Experiments were performed in the temperature range 1940-2080K at a pressure of 4.3 GPa. With the addition of 0.25 and 0.50wt.% beryllium the activation energy of the cBN formation process is found to be 45.8 and 42.0 kJ/mol, respectively. The resulting crystals showed p-type conductivity. The activation energy of the impurity carriers for the samples with 0.25 and 0.50 wt.% beryllium additions equalled 0.22 and 0.17 eV, respectively.

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Section: Methodsmentioning

confidence: 83%

Peculiarities of spontaneous crystallization of cubic boron nitride single crystal powders in the Li-B-N (H, Be) system

Gameza

2000

High Pressure Research

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“…Additions of sulfur or selenium [37,38] or some other elements of the VIb group to the reaction mixture lower the activation energy ( Table 5). The activation energy seems sensitive to the atomic mass of the S and Se elements equaling 44-45, 38-39, and 34 kJ/mol, for concentrations in the starting mixture of 0.5; 1.0 and 3.0 weight %, respectively.…”

Section: Work Of Formation Of Critical Nucleimentioning

confidence: 99%

Investigation of the Processes of Crystallization and Sintering of Cubic Boron Nitride and Its Physical Properties

Shipilo¹,

Gameza²,

Anichenko³

et al. 2000

Journal of Wide Bandgap Materials

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Nanothermodynamic analysis of the low-threshold-pressure-synthesized cubic boron nitride in supercritical-fluid systems

Wang

Yang

2004

Applied Physics Letters

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A thermodynamic model in nanoscale was developed to elucidate the nucleation of the cubic boron nitrides (c-BN) synthesized in the high-pressure and high-temperature (HPHT) supercritical-fluid systems under the conditions of the low-threshold-pressure (from 2.0±0.1 to 3.0 GPa) and low-temperature (1300–1500 K). Notably, taking the nanosize-induced interior pressure into account, the nucleation of c-BN could be driven to the new stable region from the metastable region in the general accepted equilibrium phase (P,T) diagram of BN proposed by Corrigan and Bundy, upon HPHT supercritical-fluid systems. The threshold pressure of the formation of c-BN was calculated based on our model, and these results are in excellent agreement with the experiment.

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Investigation of sulphur additions on kinetic processes of cubic boron nitride crystallization in the LiBNH system

Cited by 4 publications

References 2 publications

Peculiarities of spontaneous crystallization of cubic boron nitride single crystal powders in the Li-B-N (H, Be) system

Peculiarities of spontaneous crystallization of cubic boron nitride single crystal powders in the Li-B-N (H, Be) system

Investigation of the Processes of Crystallization and Sintering of Cubic Boron Nitride and Its Physical Properties

Nanothermodynamic analysis of the low-threshold-pressure-synthesized cubic boron nitride in supercritical-fluid systems

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