Investigation on the spin filtering properties of the organic molecules through single molecule conductivity measurement

成功构建并测试了MCBJ（机械控制断结）作为测量单分子电导和测试有机自由基自旋过滤性能的平台。与前期相比，仪器设置有了实质性的改进，实现了有机分子的单分子电导比金属原子的电导小几个数量级。对仪器的整体结构和操作程序进行了改进，减小了振动和电气噪声，并引入了压电元件，实现了结距的精确控制。为了更好的再现性，对结的制作方法也进行了改进。溶液池和支架也安装在仪器上，以允许电化学门控的溶液状态测量。以对苯二硫醇作为参比，检测仪器的性能，MCBJ仪器能够重现报告的电导。进一步优化仪器运行速度，进行统计分析，并对有机自由基的实际单分子电导和自旋过滤性能进行研究。

MCBJ (mechanically controlled break-junction) as a platform for measuring single molecule conductance and testing spin filtering properties of organic radical species was successfully built and tested. Substantial improvement in the instrumental setup compared to the preliminary stage was made to realize the single molecule conductance of organic molecule which has several order of magnitude smaller than the conductance of metal atoms. Whole the structure of the instrument and the operating program was revised to reduce vibration and electrical noise and a piezo element was introduced to make precise junction distance control. Junction fabrication method was also revised for better reproducibility. Solution cell and the mount was also installed to the instrument to allow solution state measurement for electrochemical gating. Performance of the instrument was examined with p-benzenedithiol as reference and the MCBJ instrument was able to reproduce the reported conductance. Further optimization on the operating speed of the instrument for statistical analysis and investigation on the actual single molecule conductance and spin filtering properties of organic radical species will be held in subsequent year.