High-Pressure Synthesis of Superconducting Sn3S4 Using a Diamond Anvil Cell with a Boron-Doped Diamond Heater
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2022-02-28 |
| Journal | Inorganic Chemistry |
| Authors | Ryo Matsumoto, Kensei Terashima, Satoshi Nakano, Kazuki Nakamura, Sayaka Yamamoto |
| Institutions | University of Tsukuba, Kyoto University of Advanced Science |
| Citations | 9 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Boron-Doped Diamond (BDD) for Extreme High-Pressure Synthesis
Section titled âTechnical Documentation & Analysis: Boron-Doped Diamond (BDD) for Extreme High-Pressure SynthesisâReference: High-pressure synthesis of superconducting Sn3S4 using diamond anvil cell with boron-doped diamond heater (Matsumoto et al., NIMS, Japan)
Executive Summary
Section titled âExecutive SummaryâThis research validates the critical role of Microwave Plasma-Assisted Chemical Vapor Deposition (MPCVD) Boron-Doped Diamond (BDD) films in enabling complex in situ materials science under extreme conditions.
- Functional Diamond Integration: BDD epitaxial films were successfully integrated onto diamond anvils, serving simultaneously as high-power heaters, thermometers, and electrical transport measurement terminals within a Diamond Anvil Cell (DAC).
- Extreme Environment Capability: The BDD components facilitated the synthesis of cubic Sn3S4 at pressures up to 41.1 GPa and temperatures reaching 800 K, demonstrating exceptional stability and functionality.
- Tunable Electronic Properties: Precise control over MPCVD boron doping allowed for the fabrication of both metallic BDD (for heaters/terminals, > 1021 cm-3) and semiconducting BDD (for thermometers).
- Superconductivity Discovery: The in situ transport measurements confirmed the metallic nature and subsequent superconductivity of the synthesized Sn3S4 phase.
- Maximum Performance: A maximum superconducting transition temperature ($T_{c}^{\text{onset}}$) of 13.3 K was observed at 5.6 GPa.
- Material Requirement: The study highlights the necessity of high-quality, highly durable diamond substrates (such as nano-polycrystalline diamond) for DAC components operating under ultra-high pressure.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results and methodology, demonstrating the performance achieved using BDD functional components.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Maximum Synthesis Pressure | 41.1 | GPa | Achieved during synthesis run #1 |
| Maximum Synthesis Temperature | ~800 | K | Achieved via BDD heater |
| BDD Heater Input Power | ~19 | W | Required to reach 800 K |
| BDD Boron Concentration (Metallic) | > 1021 | cm-3 | Used for heater and terminals |
| Maximum Superconducting $T_{c}^{\text{onset}}$ | 13.3 | K | Observed at 5.6 GPa |
| Maximum Superconducting $T_{c}^{\text{zero}}$ | 8.5 | K | Observed at 5.6 GPa |
| Upper Critical Field $B_{c2}(0)$ | 10.4 | T | Estimated at 5.6 GPa |
| Coherence Length $\xi(0)$ | 5.9 | nm | Estimated at 5.6 GPa |
| Diamond Anvil Culet Diameter | 300 | ”m | Typical DAC dimension |
| Gasket Hole Diameter | 200 | ”m | Typical DAC dimension |
| Transport Measurement Range | 2 - 300 | K | Using PPMS/Quantum Design |
| Raman Spectroscopy Laser Wavelength | 532 | nm | Used for structural characterization |
Key Methodologies
Section titled âKey MethodologiesâThe successful synthesis and measurement relied on advanced diamond fabrication and high-pressure techniques, all centered around MPCVD diamond technology.
- BDD Film Deposition: Patterns for the heater, thermometer, and terminals were defined using electron beam lithography.
- MPCVD Growth: Boron-doped diamond epitaxial films were grown using Microwave Plasma-Assisted Chemical Vapor Deposition (MPCVD).
- Doping Control: Boron source gas flow was precisely controlled during MPCVD to achieve two distinct material types:
- Metallic BDD: Concentration > 1021 cm-3 for low-resistance heaters and terminals.
- Semiconducting BDD: Reduced boron concentration for the BDD thermometer component.
- Anvil Preparation: The BDD components were fabricated directly onto culet-type diamond anvils. Nano-polycrystalline diamond (NPD) was identified as highly suitable for high P/T applications due to superior hardness and thermal insulation.
- DAC Assembly: Diamond anvils were mounted onto ZrO2 backup plates using Ag paste.
- Synthesis Environment: The sample was heated up to 800 K under high pressure (P > 30 GPa) within a glass tube under N2 gas flow to prevent diamond oxidation.
- Characterization: In situ measurements included X-ray Diffraction (XRD) using synchrotron radiation (30 keV, $\lambda$ = 0.4180 Ă ), Raman spectroscopy (532 nm laser), and electrical transport measurements (2-300 K, up to 7 T).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe successful implementation of BDD functional components in this high-pressure synthesis directly aligns with 6CCVDâs core expertise in MPCVD diamond engineering. We provide the necessary materials and customization services to replicate and advance this cutting-edge research.
Applicable Materials for High-Pressure Research
Section titled âApplicable Materials for High-Pressure Researchâ| Material | 6CCVD Specification | Application in DAC Research |
|---|---|---|
| Boron-Doped Diamond (BDD) | Heavy Boron Doped (Metallic) or Lightly Doped (Semiconducting) | Essential for integrated heaters, thermometers, and electrical terminals. We offer precise, tunable doping control to match the exact resistivity requirements (metallic or semiconducting). |
| Polycrystalline Diamond (PCD) | Plates/Wafers up to 125mm, Thickness up to 500 ”m | Ideal substrate material for high-pressure anvils, offering the superior hardness and thermal insulation noted in the paper (similar to NPD). |
| Single Crystal Diamond (SCD) | Thickness 0.1 ”m - 500 ”m, Ra < 1 nm polishing | Suitable for optical access anvils or as high-purity substrates where minimal defects are critical for BDD film quality. |
Customization Potential for DAC Integration
Section titled âCustomization Potential for DAC Integrationâ6CCVD provides comprehensive engineering services necessary to fabricate the complex BDD-integrated diamond anvils described in this study:
- Custom BDD Patterning: We utilize advanced lithography techniques to define intricate BDD heater and terminal patterns directly onto diamond substrates, matching the micron-scale precision required for DAC culets (e.g., 300 ”m diameter).
- Custom Dimensions and Shaping: We offer custom laser cutting and shaping services for diamond plates and wafers up to 125mm, ensuring precise culet geometry and thickness control (Substrates up to 10mm).
- Integrated Metalization: For robust electrical contact to the BDD terminals, 6CCVD offers internal metalization capabilities, including deposition of Ti, Pt, Au, Pd, W, and Cu contact layers, ensuring reliable transport measurements under extreme pressure.
- Surface Finish: Our polishing capabilities (Ra < 1 nm for SCD, Ra < 5 nm for PCD) ensure the necessary surface quality for high-resolution epitaxial BDD growth and optimal optical access within the DAC.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house team of PhD material scientists specializes in optimizing MPCVD growth recipes for functional diamond applications. We offer expert consultation to researchers working on similar high-pressure synthesis and in situ transport measurement projects, assisting with:
- Selection of the optimal diamond substrate (SCD vs. PCD) based on pressure requirements.
- Tuning BDD film properties (thickness, resistivity, thermal stability) for specific heater or sensor roles.
- Designing robust metal contacts for extreme temperature and pressure cycling.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
High-pressure techniques open exploration of functional materials in broad research fields. An established diamond anvil cell with a boron-doped diamond heater and transport measurement terminals has performed the high-pressure synthesis of a cubic Sn<sub>3</sub>S<sub>4</sub> superconductor. X-ray diffraction and Raman spectroscopy reveal that the Sn<sub>3</sub>S<sub>4</sub> phase is stable in the pressure range of <i>P</i> > 5 GPa in a decompression process. Transport measurement terminals in the diamond anvil cell detect a metallic nature and superconductivity in the synthesized Sn<sub>3</sub>S<sub>4</sub> with a maximum onset transition temperature (<i>T</i><sub>c</sub><sup>onset</sup>) of 13.3 K at 5.6 GPa. The observed pressure-<i>T</i><sub>c</sub> relationship is consistent with that from the first-principles calculation. The observation of superconductivity in Sn<sub>3</sub>S<sub>4</sub> opens further materials exploration under high-temperature and -pressure conditions.