Transport Properties of Boron-Doped Nanocrystalline Diamond (BNCD)

研究了超导掺硼纳米晶金刚石（BNCD）薄膜的性能。BNCD系统是一个高度可调的系统，其中电子载流子浓度可以通过硼掺杂水平来控制，从而允许从绝缘行为过渡到超导行为。这种材料是颗粒状的，颗粒的大小取决于薄膜的厚度和沉积过程的细节。我们目前正在发展接近超导转变温度（电导率波动）时电导率增加的理论。实验表明，这三个不同的区域具有不同的幂律行为，这被认为是由于库珀对相对于典型晶粒的大小。我们目前已经计算了所有对波动电导率的贡献，并试图将它们与我们在卡迪夫的合作者的实验数据相协调。详细的拟合有望为提取BNCD和其他颗粒超导体系的各种材料参数提供一种方法。

The research is focussed on the properties of superconducting boron-doped nanocrystalline diamond (BNCD) films.The BNCD system is a highly tuneable system, where the electron carrier concentration can be controlled by the levelof boron doping, allowing a transition from insulating to superconducting behaviour. The material is granular, with thesize of the grains depending on the film thickness and details of the deposition process. We are currently developing thetheory for the increase in electrical conductivity close to the superconducting transition temperature (the fluctuation conductivity). Experimentally this shows three distinct regions with different power law behaviours, which is believed to be due to the size of the Cooper pair relative to that of a typical grain. We have currently calculated all the contributions to the fluctuation conductivity, and are trying to reconcile them with the experimental data from our collaborators in Cardiff.Detailed fitting will hopefully provide a method for extracting various material parameters of BNCD and other granularsuperconducting systems.