arXiv subjects

Andrey Katrusha

Publications and source records attributed to Andrey Katrusha.

3 recordsLinked to original sources

arXiv2026

HPHT growth of centimeter-sized cubic boron nitride crystals

Single crystals of cubic boron nitride (cBN) exceeding 10 mm in size were grown by the high-pressure high-temperature (HPHT) temperature-gradient method using a Ni-Cr-based solvent catalyst. Compared with the previously reported maximum crystal size of approximately 3 mm, this improvement was achieved by maintaining a stable precursor flux during one week of growth at a source temperature of 1950 {\deg}C. In contrast to diamonds, which were grown with the same HPHT cell and showed nearly isometric shapes, the cBN crystals had elongated shapes. We attribute this cBN morphology to a localized growth near the BN source due to the relatively low effective diffusivity of boron and nitrogen species in the metallic solvent.

cond-mat.mtrl-sci↗

arXiv2026

Optical centers in cubic boron nitride and diamond: remarkable similarities

We present a comparative study of optical absorption and luminescence from cubic boron nitride (cBN) and diamond grown by the high-pressure high-temperature technique in the same cubic press. We note remarkable similarities in spectral and spatial dependences for these two materials. Using the previous identification of defects in diamond, we tentatively assign the optical center responsible for yellow color in some cBN crystals to substitutional oxygen at the nitrogen site, the RC1 and RC3 centers to a defect comprising substitutional oxygen and a boron vacancy in the neutral and negative charge states, respectively, the GC1 center to a nickel-related defect, the 1.816 eV (683 nm) luminescence peak to a Si-vacancy complex, and the BN1 center to an interstitial-related defect.

cond-mat.mtrl-sci↗

arXiv2020

Decoration of growth sector boundaries with single nitrogen vacancy centres in as-grown single crystal HPHT synthetic diamond

Large (> 100 mm$^3$), relatively pure (type II) and low birefringence single crystal diamond can be produced by high pressure high temperature (HPHT) synthesis. In this study we examine a HPHT sample of good crystalline perfection, containing less than 1 ppb (part per billion carbon atoms) of boron impurity atoms in the {001} growth sector and only tens of ppb of nitrogen impurity atoms. It is shown that the boundaries between {111} and {113} growth sectors are decorated by negatively charged nitrogen vacancy centres (NV$^-$): no decoration is observed at any other type of growth sector interface. This decoration can be used to calculated the relative {111} and {113} growth rates. The bulk (001) sector contains concentrations of luminescent point defects (excited with 488 and 532 nm wavelengths) below 10$^{11}$ cm$^{-3}$ (10$^{-3}$ ppb). We observe the negatively charged silicon-vacancy (SiV$^-$) defect in the bulk {111} sectors along with a zero phonon line emission associated with a nickel defect at 884 nm (1.40 eV). No preferential orientation is seen for either NV$^-$ or SiV$^-$ defects, but the nickel related defect is oriented with its trigonal axis along the <111> sector growth direction. Since the NV$^-$ defect is expected to readily re-orientate at HPHT diamond growth temperatures, no preferential orientation is expected for this defect but the lack of preferential orientation of SiV$^-$ in {111} sectors is not explained.

cond-mat.mtrl-sci↗