Vibrational and Electronic Properties of Complex Metal Oxides by Spectroscopic Ellipsometry

New Mexico State University, Las Cruces NM

Investigators

Abstract

This project is jointly funded by the Electronic and Photonic Materials (EPM) and Ceramic (CER) Programs in the Division of Materials Research. NON-TECHNICAL DESCRIPTION: This project trains students, including underrepresented minorities and women, in optical and X-ray thickness measurements of thin films (such as those used for advanced manufacturing in Rio Rancho, NM) and connects students with research at National Laboratories, especially the Center for Integrated Nanotechnologies at Sandia National Laboratories. The project determines the refractive index and absorption coefficient of novel crystalline oxides and studies the interaction of localized d- and f-electrons with atomic vibrations and itinerant s- and p-electrons in complex metal oxides. This research aims to develop new types of lasers and light detectors based on metal oxide hetero¬structures. TECHNICAL DETAILS: This project measures the optical constants of a broad range of complex metal oxides from the mid-infrared to the ultraviolet spectral region. The data is analyzed to draw conclusions on the vibrational, electronic, and transport properties of such oxides. Quantum confinement and stress effects in oxide heterostructures and intersubband transitions in oxide superlattices are also studied. Temperature is used a parameter to tune the oxide properties. Results are compared with theory to achieve a comprehensive understanding of correlated oxides. Experimental results provide adjustable parameters (such as the Hubbard U value) needed for band structure calculations. Undergraduate students engaged in this project visit local and regional high schools and perform materials physics classroom demonstrations. They also organize a week-long physics summer day camp in the New Mexico State University Physics Department.