Synthesis of Rare Earth Compounds and Study of Their Magnetic Optical and Semiconducting Properties.

摘要

The report summarizes a three year effort in the study of the synthesis of rare earth compounds and an investigation of their magnetic,optical and semiconducting properties. The development of the growth of single crystals from the simple face centered cubic magnetic insulating rare earth chalcogenides,to the more complex Th3P4type structures and lower symmetry layer compounds is described. Objectives include the synthesis of higher purity materials,the improvement of crystal perfection,and measurement of deviations from stoichiometry. Techniques for growing single crystals of varying compositions of solid solutions between di and trivalent rare earth chalcogenides and methods used for their characterization are developed. In addition the authors develop the reasoning which led to the variety of experiments referred to in the body of this report,with emphasis on the relationship between magnetic and electronic properties of these systems. The direct relationship of magnetism to the band structure is discussed,as reflected in transport,tunneling and optical measurements.