Development of time-resolved ESR apparatus for micro/thin-film samples toward the application of molecular device measurement

本研究的目的是通过对商用ESR仪器的最小修改，开发出一种易于应用于分子器件或自旋电子学研究的ESR仪器。采用商用高速DSP锁相放大器和自制外场调制单元进行检测。时间分辨ESR的灵敏度的提高是使用高速相敏检测进行的，直到1微秒的时间常数。结果表明，灵敏度得到了一定程度的提高，但也澄清了一些需要解决的问题。并利用DSP锁相放大器制作了一个简单的电路和一个检测电路，可以对使用同一ESR仪的器件进行ESR信号的电检测。我们自制了控制所有仪器的程序，使各种ESR的测量成为可能。此外，我们修改了程序，用于自旋泵，这是一个最近的热门话题，在自旋电子学。

The aim of this research is to develop ESR apparatus which can apply easily for molecular device or spintronics researches by a minimum modification of the commercial ESR apparatus. A commercial high-speed DSP lock-in amplifier and the home-made external field-modulation unit was used for the detection. The sensitivity improvement of the time-resolved ESR was carried out using high-speed phase-sensitive detection until 1 micro second of time-constant. As the results, the sensitivity improvement was achieved to some extent but some points of issue to solve were clarified. We have also made a simple electric circuit and a detection prove which can measure the electrical detection of ESR signal for the devices using the same ESR apparatus using the DSP lock-in amplifier. We made home-made programs, which control all apparatus and make the measurements of a variety of ESR possible. Furthermore, we modified the program to use for a spin-pumping that is a recent hot topic in the spintronics.