Preliminary Synthesis of Carbon Nitride Thin Films by N$_2$/CH$_4$ Microwave Plasma Assisted Chemical Vapour Deposition: Characterisation of the Discharge and the Obtained Films

Numerical investigation of transient, low-power metal vapour discharges occurring in near limit ignitions of flammable gas

This article presents an investigation of a transient (30 μs - 5 ms) electrical discharge in metal vapour with low voltage (< 50 V) and current (< 1 A), drawn between two separating electrodes. Discharges of this type are rarely studied, but are important in electrical explosion safety, as they can ignite flammable gasses. An empirical model is developed based on transient recordings of discharge voltages and currents and high speed broadband image data. The model is used for predicting the electrical waveforms and spatial power distribution of the discharge. The predicted electrical waveforms…

A simple, space constrained NIRIM type reactor for chemical vapour deposition of diamond

In this paper the design of a simple, space constrained chemical vapour deposition reactor for diamond growth is detailed. Based on the design by NIRIM, the reactor is composed of a quartz discharge tube placed within a 2.45 GHz waveguide to create the conditions required for metastable growth of diamond. Utilising largely off-the-shelf components and a modular design, the reactor allows for easy modification, repair, and cleaning between growth runs. The elements of the reactor design are laid out with the CAD files, parts list, and control files made easily available to enable replication. F…

Copper underpotential deposition on boron nitride nanomesh

The boron nitride nanomesh is a corrugated monolayer of hexagonal boron nitride (h-BN) on Rh(111), which so far has been studied mostly under ultrahigh vacuum conditions. Here, we investigate how copper underpotential deposition (upd) can be used to quantify defects in the boron nitride monolayer and to assess the potential window of the nanomesh, which is important to explore its functionality under ambient and electrochemical conditions. In dilute sulfuric acid, the potential window of h-BN/Rh(111) is close to 1 volt, i.e. larger than that of the Rh substrate, and is limited by molecular hyd…

Superconducting boron doped nanocrystalline diamond on boron nitride ceramics

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 dop…

Dielectric spectroscopy of hydrogenated hexagonal boron nitride ceramics

Hexagonal boron nitride (h-BN) is a critical material for 2D electronic devices for graphene and has attracted a considerable amount of attention owing to its structural similarity and semiconducting property. However, modifying its wide-band gap is a challenge. Hydrogenation is a potential method of altering the electrical properties, although is seldom experimentally measured. Here, the complex permittivity of h-BN after various hydrogen treatments have been investigated. For untreated h-BN, a frequency independent dielectric constant was measured ($\sim4.2 \pm0.2$) and an immeasurably low d…

原子层沉积抑制二次电子倍增：氮化钛案例研究

Multipacting mitigation by atomic layer deposition: the case study of Titanium Nitride

本研究利用原子层沉积技术精确调控氮化钛薄膜的电阻率和总电子发射产额，以抑制超导射频腔内的二次电子倍增，该方法可推广至其他相关器件。