Development of a Cryogenic Spectroscopic Ellipsometer for Materials Research and Education

University Of California-San Diego, La Jolla CA

Investigators

Abstract

This award from the Major Research Instrumentation program supports instrument development of a spectroscopic ellipsometer capable of precision measurements of the optical constants of complex materials in a broad range of frequencies (400-45,000 cm-1) both at cryogenic and elevated temperatures (5-700 K). New spectroscopic capabilities provided by the ellipsometer are essential to carry out difficult experiments pertinent to physics of strong electronic correlations in oxides, to ferromagnetism in semiconductors and many other problems. The principal advantage of ellipsometry is that this technique eliminates or minimizes experimental ambiguities connected with the determination of the optical constants using more conventional spectroscopic methods such as transmission or reflectance measurements. However, practical realization of theses advantages in the infrared IR part of the spectrum requires development of an original set-up since instruments with the needed specifications are not commercially available. Broad spectral coverage of the proposed instrument will be achieved through a cost-efficient merger of an infrared home-build ellipsometer based on a Fourier-Transform interferometer with a standard rotating analyzer apparatus for visible-near-UV operation. The project integrates research and education thus aiding towards preparation of highly skilled personnel with expertise that is in high demand both in academia and industry. The systematic studies of the optical properties of new materials can provide unique insights into the electronic structure, both carrier and lattice dynamics that is difficult or impossible to obtain through alternative experimental approaches. This award from the Major Research Instrumentation Program supports the development of a spectroscopic ellipsometer capable of precision measurements of the optical constants of complex materials in a broad range of frequencies both at cryogenic and elevated temperatures. Novel experimental capabilities provided by this instrument will facilitate resolution of some of the long-standing issues in contemporary condensed matter physics and materials science. The development program naturally integrates research and education thus aiding towards preparation of highly skilled personnel with expertise that is in high demand both in academia and industry. Research infrastructure developed in the course of this project will benefit a large group of investigators at several institutions.