TY - JOUR
T1 - Oxygen Stoichiometry Effect on Polar Properties of LaAlO3/SrTiO3
AU - Sharma, Pankaj
AU - Huang, Zhen
AU - Li, Mengsha
AU - Li, Changjian
AU - Hu, Songbai
AU - Lee, Hyungwoo
AU - Lee, Jung Woo
AU - Eom, Chang Beom
AU - Pennycook, Stephen J.
AU - Seidel, Jan
AU - Ariando,
AU - Gruverman, Alexei
PY - 2018/6/6
Y1 - 2018/6/6
N2 - Discovery of a ferroelectric-like behavior of the LaAlO3/SrTiO3 (LAO/STO) interfaces provides an attractive platform for the development of nanoelectronic devices with functionality that can be tuned by electrical or mechanical means. However, further progress in this direction critically depends on deeper understanding of the physicochemical mechanism of this phenomenon. In this report, this problem by testing the electronic properties of the LAO/STO heterostructures with oxygen stoichiometry used as a variable is addressed. Local probe measurements in conjunction with interface electrical characterization allow to establish the field-driven reversible migration of oxygen vacancies as the origin of the ferroelectric-like behavior in LAO/STO. In addition, it is shown that oxygen deficiency gives rise to the formation of micrometer-long atomically sharp boundaries with robust piezoelectricity stemming from a significant strain gradient across the boundary region. These boundaries are not ferroelectric but they can modulate the local electronic characteristics at the interface. The obtained results open a possibility to design and engineer electromechanical functionality in a wide variety of nominally nonpolar and non-piezoelectric complex oxide heterostructures and thin films.
AB - Discovery of a ferroelectric-like behavior of the LaAlO3/SrTiO3 (LAO/STO) interfaces provides an attractive platform for the development of nanoelectronic devices with functionality that can be tuned by electrical or mechanical means. However, further progress in this direction critically depends on deeper understanding of the physicochemical mechanism of this phenomenon. In this report, this problem by testing the electronic properties of the LAO/STO heterostructures with oxygen stoichiometry used as a variable is addressed. Local probe measurements in conjunction with interface electrical characterization allow to establish the field-driven reversible migration of oxygen vacancies as the origin of the ferroelectric-like behavior in LAO/STO. In addition, it is shown that oxygen deficiency gives rise to the formation of micrometer-long atomically sharp boundaries with robust piezoelectricity stemming from a significant strain gradient across the boundary region. These boundaries are not ferroelectric but they can modulate the local electronic characteristics at the interface. The obtained results open a possibility to design and engineer electromechanical functionality in a wide variety of nominally nonpolar and non-piezoelectric complex oxide heterostructures and thin films.
KW - complex oxide heterointerfaces
KW - oxygen stoichiometry
KW - polar boundaries
KW - scanning probe microscopy
UR - http://www.scopus.com/inward/record.url?scp=85046135067&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/ARC/CE170100039
U2 - 10.1002/adfm.201707159
DO - 10.1002/adfm.201707159
M3 - Article
AN - SCOPUS:85046135067
SN - 1616-301X
VL - 28
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 23
M1 - 1707159
ER -