Rutile TiO2 Single Crystal Substrates | High-Purity Wafers
High-purity Rutile Titanium Dioxide (TiO2) single crystal substrates feature a tetragonal structure engineered for advanced optics and thin-film epitaxy. Renowned for its exceptional optical birefringence and exceptionally high refractive index (approx. 2.61), Rutile TiO2 serves as an essential material for optical isolators, polarizers, beam displacers, and high-frequency microwave dielectric applications. We supply research-grade Rutile TiO2 wafers in standard (100), (110), and (001) orientations with atomic-level surface polishing (Ra < 0.5 nm). Available in standard 10 mm x 10 mm and custom dimensions with precise orientation tolerances (< 0.5 degree), our substrates deliver low defect density and high batch consistency. Contact our technical team for custom sizes and volume pricing.
Technical Specifications
| Parameter | Value |
|---|---|
| Product | TiO2 Rutile Single Crystal — Titanium Dioxide, Tetragonal, P42/mnm |
| Lattice Parameters | a = 4.594 Å, c = 2.958 Å |
| Density / Melting Pt | 4.26 g/cm³ | ~1,840-1,870°C |
| Hardness | Mohs 7 — excellent mechanical durability |
| Bandgap | 3.0 eV |
| R.I. no/ne @633nm | no=2.583, ne=2.865 — highest index of any oxide crystal; Δn=+0.282 (very high birefringence) |
| Dielectric ε | ~113 (1MHz); ∥c~180, ⊥c~90 |
| Transmission / Orientations | 0.5–4.5 µm | (100)(110)(001)(111) ±0.5° |
| Primary Applications | Glan-Taylor polarizers, optical isolators, beam displacers, photocatalytic substrates, Nb-doped conductive TiO2 electrodes |
Product Overview
TiO2 Rutile possesses the highest refractive index and largest birefringence (Δn=+0.282) of any commercially available oxide crystal — exceeding YVO4 (no=1.99) and approaching II-VI semiconductors. Combined with Mohs 7 hardness (superior chemical stability vs YVO4 and calcite), it is the material of choice for: compact Glan-Taylor polarizers, optical isolator walk-off beam displacers, and prism couplers. Princeton Powder supplies (100)(110)(001)(111), undoped and Nb-doped (2.5-10 Ω·cm), SSP/DSP, CMP epi-ready Ra<5Å.
Technical Specifications
| Parameter | Specification |
|---|---|
| Crystal Structure | Tetragonal, Rutile, P42/mnm; a=4.594Å, c=2.958Å |
| Density / Melting Pt | 4.26 g/cm³ | ~1,840-1,870°C |
| Hardness / Bandgap | Mohs 7 | 3.0 eV |
| no / ne @633nm | 2.583 / 2.865 (Δn=+0.282) |
| Dielectric ε / Transmission | ~113 (1MHz) | 0.5–4.5 µm |
| Thermal Expansion αa/αc | 7.14 / 9.19 ×10⁻⁶/K |
| Undoped Resistivity | >10⁷ Ω·cm |
| Nb:TiO2 Resistivity | 2.5-10 Ω·cm (0.05 wt% Nb) |
| Sizes / Polish | 5×5-15×15mm²; 0.5mm; SSP/DSP Ra<5Å; S/D 20/10; λ/10 flatness |
Why Choose Princeton Powder TiO2 Rutile
- Highest Index Oxide: no=2.58, ne=2.87 — exceeds YVO4 and all competitors. Enables the most compact Glan polarizers with widest acceptance angles.
- Superior Durability vs YVO4: Mohs 7 vs 5, better chemical resistance, no photorefractive damage — longer lifetime in high-power and harsh environments.
- Nb-Doped Conductive: 2.5-10 Ω·cm — dual-function: photocatalytic active layer + current-collecting electrode.
Applications
Glan-Taylor & Wollaston Polarizers
TiO2's high birefringence enables compact, wide-acceptance-angle polarizing prisms — the standard for fiber-coupled and miniaturized optical systems where YVO4's lower index requires longer crystals.
Optical Isolator Beam Displacers
TiO2 walk-off beam displacers provide larger separation angles in shorter crystals than YVO4 — enabling more compact free-space optical isolators for fiber laser and telecom applications.
Photocatalytic & TCO Substrates
Nb-doped conductive TiO2 serves as both the photocatalyst (water-splitting, CO2 reduction) and the transparent conducting electrode — eliminating separate electrode deposition steps.
FAQ
TiO2 Rutile vs YVO4 for polarizers?
TiO2: higher index (no=2.58 vs 1.99), higher Δn (0.282 vs 0.22), harder (7 vs 5), better chemical stability. YVO4: wider UV transmission, lower cost. Choose TiO2 for compact/durable polarizers; YVO4 for UV or budget applications.
Anatase vs Rutile TiO2?
This is rutile — the thermodynamically stable, high-index polymorph. Anatase has lower index (~2.5), lower density (3.89), and is used in photocatalysis — not optical components.