Optical studies of nanoscale materials incorporated in the space of zeolite crystals

Optical spectroscopy is used for the characterization of the quantum electronic state of nanoscale materials incorporated in zeolite crystals. Alkali metal clusters generated in zeolite exhibit interesting phenomena in optical properties as well as magnetic ones. Potassium clusters incorporated in zeolite LTA have shown ferromagnetism at low temperatures. The origin of the ferromagnetism was explained by the itinerant electron model. The infrared spectrum and magnetization curves, however, suggest that the itinerant electron model is not applicable to the ferromagnetism. Magnetic properties are interpreted based on the model of ferrimagnetism. Polarized micro-optical spectroscopy suggests the possibility of the one-dimensional array of potassium clusters in zeolite MOR single crystal. (C) 1997 Elsevier Science S.A.