BaTiO3 (BTO) Single Crystal Substrate for PZT/BST Epitaxy & Photorefractive Applications
High-grade BaTiO3 (BTO) single crystal substrates engineered for cutting-edge PZT/BST epitaxy, optical storage, and photorefractive applications. Renowned for outstanding ferroelectric, piezoelectric, and non-linear optical properties, our BTO crystals provide superior lattice matching for complex oxide thin-film deposition. Manufactured under strict quality standards to ensure uniform domain structures and exceptional chemical purity, making them ideal for next-generation telecommunications and microelectronics research. Available in standard 10x10mm, 5x5mm, or tailor-made custom specifications with single- or double-side optical polish. Request your quote today for competitive pricing, technical support, and reliable global distribution.
Technical Specifications
| Parameter | Value |
|---|---|
| Product | BaTiO3 (BTO) Single Crystal Substrate — Barium Titanate, Ferroelectric Perovskite |
| Crystal Structure | Tetragonal (4mm) at RT; Cubic above ~130°C Curie point; a = 3.99 Å, c = 4.04 Å |
| Density / Melting Point | 6.02 g/cm³ | ~1,610°C |
| Transmission Range | 0.43–6.30 µm |
| Refractive Indices | @633nm: no=2.416, ne=2.363 | @515nm: no=2.491, ne=2.425 |
| EO Coefficient r42 | 1,300–1,920 pm/V — among the highest of any crystal; r33=105–112 pm/V |
| Dielectric Constant | εa=3,700, εc=135 (unclamped); εa=2,400, εc=60 (clamped) |
| Piezoelectric d33 | 496 pC/N |
| Standard Orientations | <100>, <001>, <110>, <111> ±0.5° |
| Primary Applications | FeRAM/PZT/BST epitaxy substrates, EO modulators, photorefractive holographic storage, MEMS sensors/actuators |
Product Overview
BaTiO3 (BTO, Barium Titanate) is the original ferroelectric perovskite oxide — the first discovered and still one of the most technologically important ferroelectric materials. Its defining properties include an extraordinarily high electro-optic coefficient r42=1,300-1,920 pm/V (~60× LiNbO3), giant dielectric constant εa=3,700 (unclamped), excellent photorefractive SPPC reflectivity (50-80% at visible wavelengths), and piezoelectric coefficient d33=496 pC/N. Princeton Powder supplies BaTiO3 single crystal substrates in <100>, <001>, <110>, and <111> orientations, 5×5mm to Ø2″, SSP and DSP, with epi-ready CMP surface (Ra<5Å) — the standard substrate for perovskite oxide thin-film epitaxy (PZT, BST, SBT for FeRAM), electro-optic device fabrication, and photorefractive research. Single-domain (electrically poled) substrates available for EO and photorefractive device applications — eliminating the domain boundaries that scatter light in as-grown multi-domain BTO. Critical handling note: BTO must be stored above 13°C to avoid the tetragonal→orthorhombic phase transition that causes twinning.
Grade Selection Guide
| Grade | Domain State | Polish | Best For |
|---|---|---|---|
| Substrate Grade (With Domains) | As-grown 90°/180° domains | SSP/DSP CMP Ra<5Å | Thin-film epitaxy (FeRAM, PZT, BST) — domains do not affect film growth quality; most cost-effective |
| Single-Domain (Poled) | Electrically poled — domain-free | SSP/DSP CMP Ra<5Å | EO modulators, photorefractive devices — domain walls scatter light and degrade EO response; single-domain required for optical device fabrication |
| Ce-Doped / Fe-Doped | Varies | SSP/DSP | Ce: enhanced photorefractive SPPC (up to 87% at 633nm); Fe: photorefractive two-wave mixing; custom doping on request |
All substrates shipped in thermally insulated packaging with temperature monitoring — BTO must stay >13°C.
Technical Specifications
Crystal & Physical Properties
| Parameter | Specification |
|---|---|
| Crystal Structure | Tetragonal (4mm) at RT; Cubic (m3m) above ~130°C Curie point |
| Lattice Constants | a=3.99 Å, c=4.04 Å (at 26°C) |
| Density / Melting Point | 6.02 g/cm³ | ~1,610°C |
| Growth Method | Top Seeded Solution Growth (TSSG) |
| Transmission Range | 0.43–6.30 µm |
| R.I. @515nm / 633nm / 800nm | no=2.49/2.416/2.368; ne=2.425/2.363/2.324 |
| EO r42 / r33 / r13 | 1,300-1,920 / 105-112 / 8-11.7 pm/V |
| Dielectric εa / εc (unclamped) | 3,700 / 135 |
| Piezoelectric d33 | 496 pC/N |
| SPPC Reflectivity @515-633nm | 50-80% (pure); up to 87% (Ce-doped) |
| Two-Wave Mixing Gain | 10-40 cm⁻¹ |
Substrate Specifications
| Parameter | Specification |
|---|---|
| Orientations | <100>, <001>, <110>, <111> ±0.5° |
| Standard Sizes | 5×5, 10×5, 10×10, 20×20mm²; Ø1″, Ø2″ |
| Thickness / Tolerance | 0.5mm, 1.0mm ±0.05mm |
| Polish | SSP / DSP; CMP epi-ready Ra<5Å (AFM verified) |
| Dimension Tolerance | ±0.1 mm |
| Packaging | Class 100 clean bag; thermal packaging for >13°C maintenance during transit |
BaTiO3 vs LiNbO3 vs SrTiO3 — Perovskite Material Comparison
| Property | BaTiO3 (this product) | LiNbO3 | SrTiO3 |
|---|---|---|---|
| EO r42 / r33 | 1,300-1,920 / 105-112 — highest EO among oxides | N/A / 31 pm/V — weak EO for modulators | N/A — not strongly EO |
| Dielectric ε | 3,700 — giant, enabling on-chip capacitors | ε⊥=85, ε∥=29 | ~300 |
| Ferroelectric | Yes — Ps, Tc=130°C; switchable domains | Yes | No — paraelectric to ~110K (antiferrodistortive) |
| Photorefractive SPPC | 50-80% — best photorefractive oxide | Weak photorefractive; requires Fe doping | None |
| Epitaxy Substrate | Good for PZT, BST (a=3.99Å) | Not used as epitaxy substrate | Industry standard (a=3.905Å, Nb-doped) |
| Phase Stability | Tetragonal→Orthorhombic at ~13°C — requires thermal management | Trigonal — stable to ~1,140°C | Cubic→Tetragonal at ~110K — stable at RT |
Applications
Ferroelectric Thin-Film Epitaxy — FeRAM, PZT, BST Substrates
BaTiO3 is the prototypical perovskite substrate for ferroelectric thin-film growth. Its lattice constant (a=3.99Å) closely matches PZT, BST, and SBT — the capacitor dielectric materials in FeRAM memory chips. BTO's own ferroelectric properties enable integrated FeFET and FTJ devices for non-volatile, ultra-low-power memory. Princeton Powder supplies BTO with epi-ready CMP surface (Ra<5Å, AFM-verified) for perovskite oxide epitaxy.
Electro-Optic Modulators & Photorefractive Holographic Storage
BTO's r42=1,300-1,920 pm/V — the largest EO coefficient of any commercial crystal — enables EO modulators and beam deflectors with sub-volt drive requirements. Photorefractive SPPC of 50-80% (up to 87% Ce-doped) and two-wave mixing gain of 10-40 cm⁻¹ at visible wavelengths make BTO the premier material for holographic data storage and adaptive optics.
Lead-Free MEMS Piezoelectric Sensors & Actuators
BTO's d33=496 pC/N combined with lead-free composition addresses RoHS exemption concerns for PZT-containing MEMS devices. BTO thin films on BTO substrates provide the homoepitaxial quality required for high-displacement, high-reliability micro-actuators and ultrasonic transducers.
Why Choose Princeton Powder BaTiO3 Substrates
- r42=1,300-1,920 pm/V — ~60× LiNbO3: The highest EO coefficient among commercial oxide crystals — enabling EO modulators with drive voltages orders of magnitude lower than LN or KTP.
- Giant Dielectric εa=3,700: 10-30× higher than SrTiO3 or KTaO3 — enabling on-chip capacitors, tunable microwave devices, and varactors where miniaturization is critical.
- Single-Domain (Poled) Available: Substrate-grade with domains for epitaxy; single-domain poled for EO devices. Both from one supplier.
- Thermal Packaging Included: BTO must stay >13°C — Princeton Powder ships in thermally insulated boxes with temperature monitoring.
- CMP Epi-Ready Ra<5Å: AFM roughness report with every substrate.
- Custom Doping — Ce, Fe Available: Ce-doped for enhanced photorefractive response. Fe-doped for two-wave mixing. Custom dopants on request.
FAQ
Why must BaTiO3 be stored above 13°C?
BTO undergoes a tetragonal→orthorhombic phase transition at ~9-13°C. Crossing this transition causes crystallographic twinning — creating 90° domain walls that degrade EO performance and scatter light. Princeton Powder ships BTO in thermally insulated packaging with temperature monitoring. If your package arrives below 13°C, contact us immediately for replacement.
Single-domain vs "with domains" — which grade do I need?
With-domains (substrate grade): As-grown BTO contains ferroelectric domains — acceptable for thin-film epitaxy. Lower cost. Single-domain (poled): Electrically poled to remove domains — required for EO modulator and photorefractive device fabrication where domain boundaries scatter light and degrade EO response.
Can BTO substrates be used above the Curie temperature (130°C)?
Above 130°C, BTO becomes cubic (paraelectric) — ferroelectric, piezoelectric, and EO properties are lost. However, the cubic phase is perfectly suitable as an epitaxial substrate for film growth at elevated temperatures (PLD, sputtering, MOCVD typically 500-800°C). BTO returns to tetragonal upon cooling below Tc.
BaTiO3 vs LiNbO3 — which for EO modulation?
BTO: r42=1,300-1,920 pm/V — ~60× LN's r33=31 pm/V. Enables sub-volt Vπ. But BTO requires temperature stabilization (>13°C storage, Tc stability) and is more expensive. LN: mature, cheaper, wider availability, no thermal management. Choose BTO when EO drive voltage is the primary constraint. Choose LN for telecom infrastructure where reliability and cost dominate.
What surface roughness for perovskite thin-film epitaxy?
Princeton Powder's epi-ready grade provides CMP surface with Ra<5Å (0.5nm) — AFM verified per substrate. This is the surface quality required for step-flow growth of perovskite oxide thin films via PLD, sputtering, or MOCVD. TiO2-terminated surface available on request for B-site epitaxy initiation.
Available with custom doping?
Yes — Ce-doped BTO (enhanced photorefractive SPPC up to 87%), Fe-doped (photorefractive two-wave mixing), and custom doping on request. Contact our technical team with your dopant element and concentration requirements.
Research & Technical References
BaTiO3 Photorefractive Self-Pumped Phase Conjugation — Review
Journal of the Optical Society of America B, 2019 — Confirmed BTO's SPPC reflectivity of 50-80% at 515-633nm with Ce-doping boosting to 87% — the highest photorefractive efficiency of any oxide crystal. Practical takeaway: Princeton Powder's Ce-doped BTO substrates provide the enhanced photorefractive performance validated by this research for holographic storage and phase conjugation applications.
Ferroelectric BaTiO3 Thin Films for Non-Volatile Memory Applications
Advanced Functional Materials, 2021 — Demonstrated BTO-based ferroelectric tunnel junctions with >10⁴ ON/OFF ratio and >10¹⁰ cycle endurance — establishing BTO as a leading material for hafnia-free FeRAM. Practical takeaway: Princeton Powder's epi-ready BTO substrates provide the crystal quality required for high-endurance ferroelectric memory thin-film epitaxy.
Contact our crystal technical team for the full reference list.