CREATION OF NOVEL F-ELECTRON STATE BY HIGH PRESSURE AND ITS DIRECT OBSERVATION BY INFRARED SPECTROSCOPY

本研究项目的目的是用红外光谱技术研究高压下在所谓重费米子化合物中实现的导电-F电子杂化电子态。用高亮度同步辐射作为SPRING-8束线BL43IR的红外源，对装在加压发电室(钻石顶压室)中的小样品进行了困难的红外光谱测量。到目前为止，我们已经研究了Yba；lt；12&gt；，YBS，元素Yb，Ceru_4Sb；12&gt；等F-ELECIRON化合物的高压红外光谱演化。我们观察到它们的红外光谱随外压的变化很大。我们用所谓的C-F杂化带模型解释了压力引起的光谱变化。我们计划在未来进一步扩展我们对高压下F电子系统的研究。除了压力研究，我们还继续了常压下F电子系统的工作。我们观察到了许多Ce和Yb化合物的光学导电性的普遍关系。这是值得注意的，因为这样的宇宙关系只知道它们的基态性质，即Kadowaki-Wood关系

THE AIM OF THIS RESEARCH PROJECT HAS BEEN THE STUDY OF THE CONDUCTION-F ELECTRON HYBRIDIZED ELECTRONIC STATE, REALIZED IN THE SO-CALLED HEAVY FERMION COMPOUNDS, UNDER HIGH PRESSURE USING INFRARED SPECTROSCOPY TECHNIQUE. TO CARRY OUT THE DIFFICULT INFRARED SPECTROSCOPY OF SMALL SAMPLES MOUNTED IN A PRESSURE GENERTING CELL (DIAMOND ANVIL CELL), A HIGH BRILLIANCE SYNCHROTRON RADIATION WAS USED AS AN INFRARED SOURCE AT THE BEAM LINE BL43IR OF SPRING-8. WE HAVE STUDIED THE EVOLUTION OF INFRARED SPECTRA UNDER HIGH PRESSURE FOR SUCH F ELECIRON COMPOUNDS AS YbA_<12>, YbS, ELEMENTAL Yb, AND CeRu_4Sb_<12> SO FAR. WE HAVE OBSERVED LARGE CHANGES IN THEIR INFRARED SPECTRA AS A FUNCTION OF EXTERNAL PRESSURE. WE HAVE INTERPRETED THE PRESSURE-INDUCED SPECTRAL CHANGES USING THE SO-CALLED C-F HYBRIDIZED BAND MODEL. WE PLAN TO FURTHER EXTEND OUR STUDIES OF F ELECTRON SYSTEMS UNDER HIGH PRESSURE IN THE FUTURE. IN ADDITION TO THE PRESSURE STUDIES, WE HAVE ALSO CONTINUED OUR WORK OF F ELECTRON SYSTEMS AT AMBIENT PRESSURE. WE HAVE OBSERVED A UNIVERSAL RELATION REGARDING THE OPTICAL CONDUCTIVITY OF MANY Ce AND Yb COMPOUNDS. THIS IS REMARKABLE SINCE SUCH A UNIVERSAL RELATION HAD BEEN KNOWN ONLY FOR THEIR GROUND STATE PROPETIES, KNOWN AS KADOWAKI-WOODS RELATION