Cornell University
Library
Cornell UniversityLibrary

eCommons

Help
Log In(current)
  1. Home
  2. Cornell University Graduate School
  3. Cornell Theses and Dissertations
  4. Study of the Metal-Insulator Transition in LaCoO<sub>3-<i>x</i></sub> Epitaxial Films

Study of the Metal-Insulator Transition in LaCoO3-x Epitaxial Films

File(s)
Noskin_cornell_0058O_10311.pdf (888.83 KB)
Permanent Link(s)
https://doi.org/10.7298/X4W37TJ4
https://hdl.handle.net/1813/59501
Collections
Cornell Theses and Dissertations
Author
Noskin, Lindsey Erin
Abstract

Materials with temperature-dependent metal-to-insulator transitions (MIT) have gained attention for the abrupt collapse of the band gap during the transition. Various novel transistor structures which utilize MITs have been suggested and realized to produce more energy efficient transistors. To achieve practical operation temperatures for device applications, however, MIT materials with transition temperatures below 400 K are unsuitable. This work focuses on one MIT material with a high temperature transition, LaCoO3. Using oxide molecular-beam epitaxy (MBE) a series of LaCoO3-x thin films with varied La and Co compositions were grown. All films were grown on LaAlO3 (001)p substrates, which like LaCoO3, has a pseudocubic perovskite structure. The lattice mismatch is less than 0.9%. X-ray diffraction θ-2θ measurements were used to assess the structure of the films; the out-of-plane lattice constant of each film was calculated using a Nelson-Riley analysis. The temperature-dependent resistivity of each film was measured and each shows a change in electrical resistivity of more than two orders of magnitude in the MIT temperature range of 400 - 600 K, which is similar to that of bulk single crystal LaCoO3. The abruptness and magnitude of the MIT is found to be insensitive to the film composition for samples ranging from La1.1CoO3-x to LaCo1.1O3-x.

Date Issued
2018-05-30
Keywords
perovskite
•
Materials Science
•
expitaxy
•
MBE
•
MIT
•
transition
Committee Chair
Schlom, Darrell
Committee Member
Xing, Huili Grace
Degree Discipline
Materials Science and Engineering
Degree Name
M.S., Materials Science and Engineering
Degree Level
Master of Science
Type
dissertation or thesis

Site Statistics | Help

About eCommons | Policies | Terms of use | Contact Us

copyright © 2002-2026 Cornell University Library | Privacy | Web Accessibility Assistance