SYNTHESIS OF HIGH-PRESSURE PHASES AT ROOM TEMPERATURE, STRUCTURE AND PROPERTIES OF FULLERITE C60
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-06-20 |
| Journal | IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA |
| Authors | B. P. Sorokin, Dmitry Yashin, D. A. Ovsyannikov, Mikhail Popov, B. A. Kulnitskiy |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Synthesis of Ultrahard Fullerite C60
Section titled âTechnical Documentation & Analysis: Synthesis of Ultrahard Fullerite C60âThis document analyzes the research paper âSynthesis of High-Pressure Phases at Room Temperature, Structure and Properties of Fullerite C60â to provide technical specifications and highlight how 6CCVDâs advanced MPCVD diamond materials and customization services are essential for replicating and advancing this high-pressure research.
Executive Summary
Section titled âExecutive SummaryâThe research successfully investigates the synthesis and stability of ultrahard carbon phases derived from C60 fullerite under extreme pressure conditions at room temperature (RT).
- Core Achievement: Confirmation of the formation and stability of amorphous, 3D polymerized ultrahard fullerite (Phase V) under quasi-hydrostatic pressure up to 25 GPa.
- Material Property: Phase V is confirmed to possess a hardness exceeding that of natural diamond, making it a critical material for superhard applications.
- Methodology Integration: The study utilized a highly specialized experimental setup: a Diamond Anvil Cell (DAC) integrated with a Bulk Acoustic Wave (BAW) microwave resonator for in-situ monitoring.
- Phase Transitions: Structural transitions (I â II, III â IV, and IV â V) were precisely tracked using simultaneous Raman Spectroscopy (KPC) and microwave acoustic measurements (Îf/f(P)).
- Stability Confirmation: HRTEM and Raman results confirm that the ultrahard Phase V is metastable and remains stable at room temperature after the complete release of pressure.
- Future Impact: The findings provide a foundation for developing scalable synthesis technologies for ultrahard carbon materials under simpler thermodynamic conditions, potentially bypassing the need for extreme shear stress.
- 6CCVD Relevance: The entire experimental framework relies on high-quality, custom-engineered Single Crystal Diamond (SCD) anvils and specialized metalization layers, core competencies of 6CCVD.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results regarding the synthesis and characterization of C60 phases.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Maximum Applied Pressure | 25 | GPa | Achieved in the DAC setup |
| Ultrahard Phase V Formation Pressure | > 18 | GPa | Detected as partial transformation |
| Phase IV Formation Pressure | ~ 8 | GPa | Transition point from Phase III |
| Initial Fullerite Purity | 99.99 | % | Molecular C60 crystals |
| Synthesis Temperature | Room | °C | All experiments conducted at RT |
| BAW Resonator Control Overtone Frequency (f) | 1.3746 | GHz | Used for acoustic measurements |
| Diamond Raman Peak (P=0) | 1332.5 | cm-1 | Used for pressure calibration (piezo-spectroscopy) |
| Phase V Hardness | Higher than | Diamond | Confirmed by stability and prior research |
| Gasket Material | Tungsten (W) | N/A | Used to contain the C60 sample |
Key Methodologies
Section titled âKey MethodologiesâThe experiment relied on a complex, integrated high-pressure system combining mechanical compression with advanced in-situ sensing techniques.
- High-Pressure Generation: A Diamond Anvil Cell (DAC) was employed to generate quasi-hydrostatic pressures up to 25 GPa on the C60 sample contained within a tungsten gasket.
- Integrated Microwave Acoustics: The upper diamond anvil was modified with a layered piezoelectric structure (Al/ASN/Mo) to function as a Bulk Acoustic Wave (BAW) resonator, enabling in-situ measurement of acoustic properties.
- Pressure Measurement: Pressure was calibrated using the Raman shift of the stressed diamond anvil tip (the 1332.5 cm-1 line) via a Renishaw inVia Raman microscope spectrometer.
- Phase Monitoring (Raman): Raman spectra of the fullerite were collected simultaneously to track structural changes, noting the merging of the Ag(2) line into a broad 1550-1600 cm-1 line, characteristic of the ultrahard Phase V.
- Acoustic Monitoring: The relative frequency shift (Îf/f(P)) and Q-factor of the 1.3746 GHz BAW overtone were measured using an Agilent E5071C ENA vector network analyzer to detect anomalies corresponding to structural phase transitions.
- Loading Cycle: The sample underwent two complete pressure cycles (loading up to 24-25 GPa and subsequent unloading to 0 GPa) to confirm the stability and metastability of the resulting phases.
- Ex-Situ Characterization: Post-release microstructural analysis was performed using High-Resolution Transmission Electron Microscopy (HRTEM/ĐĐĐ-ĐĐ ) to confirm the amorphous, metastable structure of Phase V.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research demonstrates a critical need for high-precision, custom-engineered diamond componentsâspecifically, the SCD anvils and the integrated thin-film structures required for the BAW resonator. 6CCVD is uniquely positioned to supply these advanced materials and services.
| Research Requirement | 6CCVD Applicable Materials & Services | Technical Specification Match |
|---|---|---|
| High-Quality Diamond Anvils | Optical Grade Single Crystal Diamond (SCD) Substrates. SCD is required for maximum mechanical strength, low birefringence, and optical transparency for Raman measurements. | We provide SCD plates up to 500 ”m thick, ensuring the structural integrity necessary for pressures up to 25 GPa and beyond. |
| Integrated BAW Resonator Substrate | Custom SCD Substrates with Precision Polishing. The integration of the Al/ASN/Mo stack requires an extremely smooth surface finish on the diamond. | SCD polishing capability to Ra < 1 nm, ensuring optimal thin-film adhesion and minimal acoustic scattering losses for the BAW resonator. |
| Complex Thin-Film Deposition | Advanced Custom Metalization Services. The BAW resonator requires a specific layered structure (Al/ASN/Mo). 6CCVD offers internal metalization capabilities. | We routinely deposit refractory metals (Ti, W, Mo) and noble metals (Au, Pt, Pd, Cu), allowing for the precise fabrication of custom electrode and piezoelectric stacks on diamond surfaces. |
| Custom Dimensions for DAC | Custom Dimensions and Laser Cutting. DAC anvils require specific geometries and thicknesses for optimal pressure distribution and resonator performance. | We offer custom dimensions for plates/wafers up to 125mm (PCD) and SCD substrates up to 10mm thick, tailored to specific DAC designs. |
| Extending Ultrahard Carbon Research | Expert Engineering Support. The synthesis of ultrahard carbon materials is a frontier in materials science, closely related to 6CCVDâs expertise in carbon allotropes. | Our in-house PhD team can assist researchers with material selection (e.g., selecting appropriate SCD grades or Boron-Doped Diamond (BDD) for conductive high-pressure experiments) for similar High-Pressure Carbon Synthesis projects. |
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Studies of the structure and properties of C60 fullerite phases, including ultrahard ones, continue to be relevant. Such interest is associated with the need to obtain large-scale samples suitable not only for comprehensive research, but also for expected practical applications. The complexity of the synthesis of such materials stimulates the search for new approaches in the field of materials science of nanostructured carbon materials and technologies for their production. The article describes studies of changes in the structure of C60 fullerite under high pressure at room temperature using microwave acoustics, Raman scattering and high-resolution transmission electron microscopy (HRTEM). To achieve pressure up to 25 GPa, a high-pressure chamber on diamond anvils with a built-in microwave resonator on a longitudinal bulk acoustic wave (BAW-resonator) was used. The Raman spectra of the stressed top of the diamond anvil and fullerite were used to determine both the pressure and the fullerite phase, respectively. The dependence of the relative frequency shift of the control overtone of the BAW-resonator at a frequency of f = 1.3746 GHz on the pressure as the Îf/f(P) was obtained. Features of the Îf/f(P) curve are associated with structural changes in fullerite, in particular, with the transitions of fullerite from the first to the second and from the third to the fourth phases. At a pressure above 18 GPa, a partial transformation into an amorphous ultrahard phase V is detected, in which fullerite has a hardness higher than that of diamond. The results of such methods as Raman, HRTEM and microwave acoustics confirm the stability of phase V at room temperature. The obtained results can be used, with appropriate scaling, to develop a technology for the synthesis of fullerite in the ultrahard phase V under simpler thermodynamic conditions. For citation: Sorokin B.P., Yashin D.V., Ovsyannikov D.A., Popov M.Yu., Kulnitskiy B.A., Asafiev N.O., Blank V.D. Synthesis of high-pressure phases at room temperature, structure and properties of fullerite C60. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 9. P. 66-74. DOI: 10.6060/ivkkt.20256809.10y.