Alexandria Digital Research Library

Emergent phenomena in Mott/band insulator heterostructures

Author:
Moetakef, Pouya
Degree Grantor:
University of California, Santa Barbara. Materials
Degree Supervisor:
Susanne Stemmer
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2013
Issued Date:
2013
Topics:
Engineering, Materials Science
Keywords:
Molecular beam epitaxy
Mott insualtor
Two-dimenstional electron gas
Rare earth titanate
Perovskite oxide
Magnetism
Genres:
Online resources and Dissertations, Academic
Dissertation:
Ph.D.--University of California, Santa Barbara, 2013
Description:

The discovery of a two dimensional electron gas (2DEG) at the interface of two insulating oxides (such as LaAlO3/SrTiO 3) has attracted a significant amount of attention for novel oxide based electronics and fundamental physics studies. While most studies have been focused on LaAlO3/SrTiO3 heterostructures less attention has been given to other material systems. Here, we present recent results on a different material system, GdTiO3/SrTiO3. GdTiO 3 is a ferrimagnetic Mott insulator with a polar (001)c surface, while SrTiO3 is a band insulator with a non-polar (001) surface. In this study, GdTiO3 and SrTiO3 layers were grown by hybrid molecular beam epitaxy. Electrical measurements showed the formation of a two-dimensional electron gas (2DEG) at the GdTiO3/SrTiO 3 interface with total sheet carrier density of ~ 3x10 14 cm-2 per interface. The staggered band alignment between GdTiO3 and SrTiO3 causes the 2DEG to be located on the SrTiO3 side of the interface. Shubnikov-de Haas oscillations of the longitudinal resistance in a quantizing magnetic field were observed, indicating two-dimensionality of the electron gas. Ferromagnetic behavior was observed in both GdTiO3/SrTiO3 (where SrTiO 3 is doped by the interface) and La-doped SrTiO3 systems. We also discuss electron correlation effects in this system.

Physical Description:
1 online resource (250 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f39p2zmw
ISBN:
9781303426421
Catalog System Number:
990040770730203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Pouya Moetakef
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