Heteroepitaxy of strained and not-strained ferroelectric superlattices and their electric properties
- Osaka Univ., Ibaraki, Osaka (Japan). Inst. for Scientific and Industrial Research
Bismuth based artificial superlattices have been formed by a layer-by-layer laser deposition with in-situ monitoring of RHEED. The Bi{sub 2}O{sub 2}/Wo{sub 6}, Bi2O{sub 2}/SrTa{sub 2}O{sub 9}, Bi{sub 2}O{sub 2}/SrTa{sub 2}O{sub 9}/SrTiO{sub 3} and Bi{sub 2}O{sub 2}/SrTa{sub 2}O{sub 9}/BaTiO{sub 3} are constructed epitaxially by a single, double and triple perovskite layers sandwiched by Bi{sub 2}O{sub 2} layers, respectively. The dielectric constant increases with increasing the number of perovskite layers. And the D-E hysteresis loop (ferroelectric properties) appears along the c-axis direction in odd perovskite layers (n = 1 and 3). The authors have also formed the SrTiO{sub 3}/BiWO{sub 6}/SrTiO{sub 3} multilayers. With this combination, the STO layers are isolated by the BWO layers. The dimensionality of STO layer can be controlled by changing the thickness of BWO layers. Below the BWO thickness of 500 {angstrom}, the {var_epsilon}{sub r} increases monotonously with decreasing the BWO thickness. Therefore, the coulomb force, which is in proportion to inverse of the distance, plays an essential role for the dielectric constant. The formation of artificially constructed ferroelectric films by a layer-by-layer deposition method will be discussed and an essential approach to elucidate the mechanism of ferroelectricity.
- OSTI ID:
- 392153
- Report Number(s):
- CONF-951155--; ISBN 1-55899-304-5
- Country of Publication:
- United States
- Language:
- English
Similar Records
X-ray analysis of strain distribution in two-step grown epitaxial SrTiO{sub 3} thin films
Related Subjects
42 ENGINEERING
BISMUTH OXIDES
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
DIELECTRIC PROPERTIES
ELECTRON DIFFRACTION
ENERGY BEAM DEPOSITION
EXPERIMENTAL DATA
FERROELECTRIC MATERIALS
LASERS
LAYERS
MEMORY DEVICES
MORPHOLOGY
PEROVSKITES
STRONTIUM OXIDES
TANTALUM OXIDES
TITANIUM OXIDES
TUNGSTEN OXIDES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY