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Title: Optical Study of the Free Carrier Response of LaTiO 3/SrTiO 3 Superlattices

Abstract

We used infrared spectroscopic ellipsometry to investigate the electronic properties of LaTiO{sub 3}/SrTiO{sub 3} superlattices (SLs). Our results indicated that, independent of the SL periodicity and individual layer thickness, the SLs exhibited a Drude metallic response with sheet carrier density per interface {approx}3x10{sup 14}cm{sup -2}. This is probably due to the leakage of d electrons at interfaces from the Mott insulator LaTiO{sub 3}to the band insulator SrTiO{sub 3}. We observed a carrier relaxation time {approx}35fs and mobility {approx}35cm2V-1s-1 at 10 K, and an unusual temperature dependence of carrier density that was attributed to the dielectric screening of quantum paraelectric SrTiO{sub 3}.

Authors:
 [1];  [1];  [2];  [3];  [3];  [3];  [1]
  1. Seoul National University
  2. ORNL
  3. University of Fribourg
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
930911
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 99
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CARRIER DENSITY; DIELECTRIC MATERIALS; ELECTRONS; ELLIPSOMETRY; PERIODICITY; RELAXATION TIME; SUPERLATTICES; TEMPERATURE DEPENDENCE; THICKNESS

Citation Formats

Seo, S. S. A., Choi, W. S., Lee, Ho Nyung, Yu, L., Kim, K. W., Bernhard, C, and Noh, Tae Won. Optical Study of the Free Carrier Response of LaTiO3/SrTiO3 Superlattices. United States: N. p., 2007. Web. doi:10.1103/PhysRevLett.99.266801.
Seo, S. S. A., Choi, W. S., Lee, Ho Nyung, Yu, L., Kim, K. W., Bernhard, C, & Noh, Tae Won. Optical Study of the Free Carrier Response of LaTiO3/SrTiO3 Superlattices. United States. doi:10.1103/PhysRevLett.99.266801.
Seo, S. S. A., Choi, W. S., Lee, Ho Nyung, Yu, L., Kim, K. W., Bernhard, C, and Noh, Tae Won. Mon . "Optical Study of the Free Carrier Response of LaTiO3/SrTiO3 Superlattices". United States. doi:10.1103/PhysRevLett.99.266801.
@article{osti_930911,
title = {Optical Study of the Free Carrier Response of LaTiO3/SrTiO3 Superlattices},
author = {Seo, S. S. A. and Choi, W. S. and Lee, Ho Nyung and Yu, L. and Kim, K. W. and Bernhard, C and Noh, Tae Won},
abstractNote = {We used infrared spectroscopic ellipsometry to investigate the electronic properties of LaTiO{sub 3}/SrTiO{sub 3} superlattices (SLs). Our results indicated that, independent of the SL periodicity and individual layer thickness, the SLs exhibited a Drude metallic response with sheet carrier density per interface {approx}3x10{sup 14}cm{sup -2}. This is probably due to the leakage of d electrons at interfaces from the Mott insulator LaTiO{sub 3}to the band insulator SrTiO{sub 3}. We observed a carrier relaxation time {approx}35fs and mobility {approx}35cm2V-1s-1 at 10 K, and an unusual temperature dependence of carrier density that was attributed to the dielectric screening of quantum paraelectric SrTiO{sub 3}.},
doi = {10.1103/PhysRevLett.99.266801},
journal = {Physical Review Letters},
number = ,
volume = 99,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}