Strontium Titanate SrTiO3
SrTiO3 is widely used as a substrate for ferroelectrics and superconducting thin films, as it possesses a typical perovskite structure.
Characteristics
| Composition | SrTiO3 |
|---|---|
| Crystal system | Cubic |
| Space group | Pm3m (Perovskite) |
| Lattice constant | a=0.3905 nm |
| Melting point | 2080 ℃ |
| Growth method | Verneuil method |
| Density | 5.122 g/cm3(20 ℃) |
| Dielectric constant | 310 (27℃,1 MHz) |
| Thermal expansion coefficient | 11.1×10-6/℃（r.t.～1000℃） |
| Phase transition | 110 K (tetragonal ⇔ cubic) |
| Refractive index | 2.407 (at 589 nm) |
Standard Specs
| SrTiO3 | Nb(0.05 wt%):SrTiO3 Nb≒0.1 at% | Nb(0.5 wt%):SrTiO3 Nb≒1.0 at% | |
|---|---|---|---|
| Purity | >99.98 % | >99.98 % | >99.98 % |
| Resistivity (Ω・cm) | >107 | 7～10×10-2 | 3～7×10-3 |
| Career density (cm-3) | ― | 1～2×1019 | 1～2×1020 |
| Orientation (Tolerance: ±0.5°) | (100), (110), (111) | (100), (110), (111) | (100), (110), (111) |
| Size (Outer size tolerance: ±0.1 mm / Thickness tolerance: ±0.05 mm) | 10×10×0.5t 15×15×0.5t |
10×10×0.5t 15×15×0.5t |
10×10×0.5t 15×15×0.5t |
| Polishing | One-side / Both-side | One-side / Both-side | One-side / Both-side |
| Surface roughness | Ra ≦ 1.0 nm Rmax ≦ 5.0 nm |
Ra ≦ 1.0 nm Rmax ≦ 5.0 nm |
Ra ≦ 1.0 nm Rmax ≦ 5.0 nm |
| Flatness (λ=632.8 nm) | 10×10×0.5 t :≦λ 15×15×0.5 t : ≦1.5λ |
10×10×0.5 t :≦λ 15×15×0.5 t : ≦1.5λ |
10×10×0.5 t :≦λ 15×15×0.5 t : ≦1.5λ |