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Chemistry, growth kinetics, and epitaxial stabilization of Sn2+ in Sn-doped SrTiO3 using (CH3)6Sn2 tin precursor.
- Source :
- APL Materials; 2016, Vol. 4 Issue 12, p126111-1-126111-7, 7p
- Publication Year :
- 2016
-
Abstract
- PbTiO<subscript>3</subscript>-based ferroelectrics have impressive electroactive properties, originating from the Pb<superscript>2+</superscript> 6s<superscript>2</superscript> electron lone-pair, which cause large elastic distortion and electric polarization due to cooperative pseudo Jahn-Teller effect. Recently, tin-based perovskite oxide (SnTiO<subscript>3</subscript>) containing Sn<superscript>2+</superscript> and a chemistry similar to that of the 6s<superscript>2</superscript> lonepair has been identified as a thermally stable, environmentally friendly substitute for PbTiO<subscript>3</subscript>-based ferroelectrics. However experimental attempts to stabilize Sn<superscript>2+</superscript> on the A-site of perovskite ATiO<subscript>3</subscript> have so far failed. In this work, we report on the growth of atomically smooth, epitaxial, and coherent Sn-alloyed SrTiO<subscript>3</subscript> films on SrTiO<subscript>3</subscript> (001) substrates using a hybrid molecular beam epitaxy approach. With increasing Sn concentration, the out-of-plane lattice parameter first increases in accordance with the Vegard's law and then decreases for Sn/(Sr+Ti+Sn) at. % ratio > 0.1 due to the incorporation of Sn<superscript>2+</superscript> at the A-site. Using a combination of high-resolution X-ray photoelectron spectroscopy and density functional calculations, we show that while majority of Sn is on the B-site, there is a quantitatively unknown fraction of Sn being consistent with the A-site occupancy making SrTiO<subscript>3</subscript> polar. A relaxor-like ferroelectric local distortion with monoclinic symmetry, induced by A-site Sn<superscript>2+</superscript>, was observed in Sn-doped SrTiO<subscript>3</subscript> with Sn/(Sr+Ti+Sn) at. % ratio = 0.1 using optical second harmonic generation measurements. The role of growth kinetics on the stability of Sn<superscript>2+</superscript> in SrTiO<subscript>3</subscript> is discussed. [ABSTRACT FROM AUTHOR]
- Subjects :
- PEROVSKITE analysis
STRONTIUM titanate
TIN
Subjects
Details
- Language :
- English
- ISSN :
- 2166532X
- Volume :
- 4
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- APL Materials
- Publication Type :
- Academic Journal
- Accession number :
- 120512949
- Full Text :
- https://doi.org/10.1063/1.4972995