Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥7,000,000 (Direct Cost: ¥7,000,000)
|
Research Abstract |
We challenged the experiments combining the x-ray analysis and the scanning tunneling microscope (STM) for the first time. Therefore, we had to investigate the optimal experimental conditions, the origin of the obtained signal, and the information which was contained in the signal, step by step. Although we could not obtain the good results for more than 1 year. We found that the STM tip current was measured when the x-rays irradiated the sample's surface under that condition where the usual tunnel current could not be detected. We refereed to this current as the x-ray excited current. Next, we investigated the dependencies of the x-ray excited current on the incident angle of the x-rays, the kind of the gases, the gas pressure, the bias voltage, the x-ray intensity, and kind of the sample. As a result, it was found that the x-ray excited current originated from the electrons emitted from the sample's surface by x-ray irradiation, and that the electrons ionized the gaseous atoms and molecules and produced many electrons when the electrons approached toward the molecules and produced many electrons approached toward the STM tip. Now we have tried the micro-analysis by measuring the x-ray excited current.
|