Development of Multiple microspectometer in the Visible/Vacuum-Ultraviolet Region

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In the synthesizing process of new materials, it is very important to make optical measurements in the fundamental absorption region for the assignment of the materials, the evaluation of impurity- and carrier- concentration and the study of electronic structures. However, at the early stage of the synthesizing process, it is rare to be able to grow crystals large enough to make optical measurements. Therefore the purpose of this study is to design and fabricate a scanning multiple microspectrometer which enables absorption/reflection, fluorescence and photoelectron measurements in the 600-30 nm region. The Schwarzschild objective composed of a concave and a convex mirrors is used to get a microbeam. The sample can be cooled down to the liquid nitrogen temperature. At the first time, the Schwarzschild objective was checked in the visible-ultraviolet region. The reflectance of a high Tc material of BiィイD22ィエD2SrィイD22ィエD2CaCuィイD22ィエD2OィイD28ィエD2 could be measured on a small flat surface of its whisker crystals. The measured reflectance is the highest one obtained so far. The Schwarzschild objective was equipped with a Seya-Namioka monochromator for the measurements in the vacuum ultraviolet. A fluorescence spectrometer was attached to it. A photoelectron spectrometer using He-I resonance line was already fabricated. By the use of the Schwarzschild objective equipped with the Seya-Namioka monochromator, the absorption/reflection, fluorescence and the photoelectron measurements should be carried out. For it, two color multilayers were developed, reflecting not only He-I and He-II resonance lines for the photoelectron spectroscopy, but also the light in their longer wave length region for the other spectroscopy. The two-color multilayers will be evaporated onto the grating of the Seya-Namioka monochromator and the mirrors of the Schwarzschild objective. The microspectroscopy of magnetic materials of small size will be made in near future.