Superconducting boron doped nanocrystalline diamond on boron nitride ceramics

Abstract

In this work we have demonstrated the growth of nanocrystalline diamond on boron nitride ceramic. We measured the zeta potential of the ceramics to select the diamond seeds. Diamond was then grown on the seeded ceramics using a microwave chemical vapour deposition system. A clear difference was found between the samples which were seeded with nanodiamond and the ones not seeded before growth. Raman spectroscopy confirmed the excellent quality of the diamond film. Dielectric measurements showed an increase in the dielectric constant of the material after diamond growth. The diamond was also doped with boron to make it superconducting. The film had a transition temperature close to 3.4K. Similar strategies can be applied for growth of diamond on other types of ceramics.

Nucleation of diamond films on heterogeneous substrates: a review

“…102 Similar results have been seen for other surfaces like silicon dioxide, silicon, silicon carbide to name a few. The nanoseeding technique is now being routinely used to grow diamond on ceramics, 105,106 cutting tools [107][108][109][110] etc. Researchers have also used ND solutions for selective seeding using ink-jet style writing technology, [111][112][113][114] contact printing, 115 photolithography [116][117][118] or masking 116,119,120 to dene diamond structures without post diamond growth lithography and etching.…”

Enhanced strength of nano-polycrystalline diamond by introducing boron carbide interlayers at the grain boundaries

“…Diamond, the hardest known material, has been attracting continuous interest for decades in cutting tools and applications in high-pressure science because of its excellent mechanical properties, high thermal conductivity and chemical stability. [1][2][3][4][5][6][7][8] However, the great challenge to shape, limited physical dimensions and high cost of nearly perfect singlecrystal (sc) diamonds have severely limited their widespread technological application in some extreme environments. In addition, previous studies have found that the inherent brittle strength would increase obviously with the increase of hardness of diamond.…”

Dielectric Spectroscopy of Hydrogen-Treated Hexagonal Boron Nitride Ceramics

“…The result is a decrease in the real part and a loss peak at the relaxation frequency of 1/τ . The h-BN samples are commercially obtained with details of the material synthesis detailed elsewhere 19 . Briefly, the hot-pressed h-BN substrates have approximate dimensions of 0.5 × 10 × 10 mm.…”

“…Before CVD diamond growth a pre-baking stage was required for the substrates before diamond seeding using a hydrogen terminated colloid solution. After seeding, microwave plasma assisted CVD was carried out using a Seki Technotron AX6500 (4 kW at 50 Torr) in a 3% CH 4 / H 2 gas mixture 19 .…”

“…The measured dielectric constant of the h-BN sample gave approximately 4.3±0.2 from 1 kHz to 10 MHz using the PPC method, in close agreement with the analytically calculated out-of-plane value 22 . Since the material is a compressed ceramic, an anisotropic value is not obtained, rather an averaged value of various directions, which is clear from the SEM images of the interface 19 . With increasing frequency, there is minimal change with a value of 4.2±0.1 obtained using the BCP method from 10 MHz to 10 GHz.…”