TY - JOUR
T1 - Crystal structures and electrical properties of epitaxial BiFeO3 thin films with (001), (110), and (111) orientations
AU - Sone, Keita
AU - Naganuma, Hiroshi
AU - Miyazaki, Takamichi
AU - Nakajima, Takashi
AU - Okamura, Soichiro
PY - 2010/9
Y1 - 2010/9
N2 - BiFeO3 (BFO) films were formed on (001), (110), and (111) La-doped SrTiO3 single-crystal substrates. All the films were epitaxially grown and had mainly rhombohedral structure. The BFO film formed on the (001) substrate had only a (001) component whereas the BFO films on (110) and (111) substrates had (1̄10) and (1̄11) components, respectively. The (001), (110), and (111) epitaxial BFO films showed the remanent polarizations of 63, 84, and 106 μC/cm2, respectively. It seems that the (1̄10) and (1̄11) components were changed to (110) and (111) ones, respectively, by applying an external voltage. The (001) epitaxial BFO film showed marked asymmetry in its electrical properties. It was found that the (001) epitaxial BFO film had a thin tetragonal layer with spontaneous polarization fixed in the downward direction near the substrate. Finally, we concluded that this tetragonal layer caused the accumulation of space charges at the interface, causing a downward built-in field to be generated. The downward build-in field facilitated the switching of upward polarization and caused asymmetric relaxation.
AB - BiFeO3 (BFO) films were formed on (001), (110), and (111) La-doped SrTiO3 single-crystal substrates. All the films were epitaxially grown and had mainly rhombohedral structure. The BFO film formed on the (001) substrate had only a (001) component whereas the BFO films on (110) and (111) substrates had (1̄10) and (1̄11) components, respectively. The (001), (110), and (111) epitaxial BFO films showed the remanent polarizations of 63, 84, and 106 μC/cm2, respectively. It seems that the (1̄10) and (1̄11) components were changed to (110) and (111) ones, respectively, by applying an external voltage. The (001) epitaxial BFO film showed marked asymmetry in its electrical properties. It was found that the (001) epitaxial BFO film had a thin tetragonal layer with spontaneous polarization fixed in the downward direction near the substrate. Finally, we concluded that this tetragonal layer caused the accumulation of space charges at the interface, causing a downward built-in field to be generated. The downward build-in field facilitated the switching of upward polarization and caused asymmetric relaxation.
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U2 - 10.1143/JJAP.49.09MB03
DO - 10.1143/JJAP.49.09MB03
M3 - Article
AN - SCOPUS:78049325093
SN - 0021-4922
VL - 49
JO - Japanese Journal of Applied Physics
JF - Japanese Journal of Applied Physics
IS - 9 PART 2
M1 - 09MB03
ER -