World First for Diamond in Synchrotron-Based IR Photothermal Nanospectroscopy
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2016-07-03 |
| Journal | Synchrotron Radiation News |
| Authors | Gianfelice Cinque, Chris S. Kelley, Mark D. Frogley, Jacob Filik, Katia Wehbe |
| Institutions | Oxford Lasers (United Kingdom), Central Laser Facility |
| Citations | 3 |
| Analysis | Full AI Review Included |
Technical Analysis and Documentation for 6CCVD
Section titled âTechnical Analysis and Documentation for 6CCVDâWorld First for Diamond in Synchrotron-Based IR Photothermal Nanospectroscopy
Section titled âWorld First for Diamond in Synchrotron-Based IR Photothermal NanospectroscopyâExecutive Summary
Section titled âExecutive SummaryâThis paper reports a breakthrough in nanoscale vibrational spectroscopy, demonstrating the Resonance-Enhanced AFM-IR (RE-AFMIR) technique utilizing broadband Synchrotron IR (SR-IR) illumination. This methodology is critically dependent on high-quality optical pathways, a core specialty of 6CCVD.
- Breakthrough Technique: World-first coupling of Atomic Force Microscopy (AFM) with broadband Synchrotron Infrared (SR-IR) radiation for Photothermal Nanospectroscopy (RE-AFMIR).
- Nanoscale Resolution: Achieved a spatial resolution of 100 nm, successfully measuring absorption spectra below the optical diffraction limit (a resolution improvement of >10x over conventional IR microscopy).
- Direct Absorption Measurement: The photothermal technique yields truly linear spectra, proportional to sample thickness, offering a major advantage over surface-limited scattering methods.
- High-Flux Advantage: Utilizes SR-IR, which is 100 to 1000 times brighter than conventional IR sources in the mid-far-IR range, enabling faster data acquisition (5-15 minutes per spectrum).
- Application Potential: Enables non-destructive, quantitative analysis of bulk properties and micromolecular changes in soft organic materials, including biomedical specimens, single cells, and nanocomposites.
- 6CCVD Relevance: Requires ultra-pure, high-quality diamond optical components (windows, substrates) capable of handling high-flux synchrotron radiation while maintaining thermal and mechanical stability.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the research paper detailing the performance and parameters of the RE-AFMIR setup:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Spatial Resolution Achieved | 100 | nm | Successfully exceeds the IR diffraction limit. |
| Spectral Acquisition Time (Initial) | 5 to 15 | minutes | Time required for one near-field IR-SR spectrum. |
| Brightness Enhancement (SR-IR) | 100 - 1000 | times | Compared to conventional broadband IR sources (in the mid-far-IR). |
| Illumination Area Diameter | 10 to 100 | ”m | Size of the illuminated spot on the sample. |
| Chopper Rotation Speed | ~20,000 | rpm | Modulates the IR beam at the AFM cantilever resonance. |
| Detectable Temperature Change | < 0.01 | °C | Required to measure sub-atomic thermal expansion. |
| IR Spectral Range Utilized | Near-IR up to Far-IR (THz) | - | Available range on the MIRIAM beamline (B22). |
| Target Acquisition Speed Reduction | Factor of 10 | - | Goal for practical image mapping collection. |
| Wavenumber Range (Figure 2) | 4000-1000 | cm-1 | Spectral range integrated across the full absorbance measurement. |
Key Methodologies
Section titled âKey MethodologiesâThe technical breakthrough relies on carefully engineered optical and mechanical components operating at resonance.
- Source Utilization: Broadband Synchrotron Radiation (SR-IR) was sourced from the Diamond Light Source MIRIAM beamline (B22) for high intensity and spectral range coverage.
- IR Beam Relay: The SR-IR light was relayed into an interferometer using high-precision ellipsoidal and toroidal mirrors.
- Beam Modulation: An ultrafast chopper spinning at approximately 20,000 rpm was used to modulate the illumination beam.
- Resonance Enhancement: The chopping frequency was precisely tuned to the mechanical resonance frequency of the AFM cantilever to maximize the oscillation amplitude and signal strength.
- Focusing Geometry: The modulated SR-IR was focused through a bottom objective, illuminating the sample directly beneath the AFM tip.
- Signal Detection (RE-AFMIR): Localized absorption of IR photons causes rapid thermal expansion (heating pulse) in the sample, which is detected by the AFM cantilever tip oscillating in contact mode.
- Spectral Correlation: Correlating the infrared wavelength with the oscillation amplitude yields a quantitative, linear IR absorption spectrum at the nanoscale.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe advanced synchrotron nanospectroscopy described in this research requires materials that offer superior optical transmission, mechanical robustness, and thermal stability under high flux, which are hallmarks of 6CCVDâs MPCVD diamond.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend this highly sensitive research, especially in high-flux synchrotron environments, researchers require optical components made from ultra-low defect materials.
- Optical Grade Single Crystal Diamond (SCD): Essential for IR windows, prisms, and beam splitters where maximum transmission across the entire MIRIAM spectral range (Near-IR to Far-IR/THz) is required. Our Optical Grade SCD offers superior purity, minimizing internal absorption and thermal blooming caused by high SR-IR flux.
- High-Purity Polycrystalline Diamond (PCD): Ideal for high-stability mounting substrates or thermal spreaders surrounding the measurement area, leveraging diamondâs unparalleled thermal conductivity for rapid heat dissipation.
- Custom Thickness SCD: Needed for beamline optics optimized for specific spectral transmission regions, particularly for thin windows (0.1 ”m) to minimize attenuation or thick substrates (up to 10 mm) for mechanical stability.
Customization Potential
Section titled âCustomization PotentialâThe experimental setup detailed in the paper (e.g., custom optical path alignment, specialized chopper interaction) frequently necessitates custom-dimensioned optics. 6CCVD is an ideal partner for these requirements:
| Capability | Specification | Application Relevance |
|---|---|---|
| Custom Dimensions | Plates/wafers up to 125 mm (PCD) | Large optical windows or support wafers required in beamline instrumentation. |
| Precision Thickness | SCD (0.1 ”m to 500 ”m) | Ultra-thin optical windows for minimal absorption and stable transmission. |
| High-Precision Polishing | Ra < 1 nm (SCD) | Critical for minimizing scatter loss and ensuring high optical fidelity within the interferometer and focusing path. |
| Advanced Metalization | Au, Pt, Pd, Ti, W, Cu | Internal capability to apply complex metal stacks for contacts, bonding, or specialized mirror coatings required in custom beamline optics. |
Engineering Support
Section titled âEngineering SupportâThe successful implementation of RE-AFMIR demonstrates the growing need for specialized diamond materials in cutting-edge vibrational analysis. 6CCVDâs in-house PhD team provides consultative support for engineers requiring thermal, optical, or electronic diamond components.
We can assist researchers in selecting the optimal diamond grade and geometry necessary for Synchrotron IR Photothermal Nanospectroscopy projects, ensuring material properties support:
- Maximizing IR transmission across the broadband spectral range.
- Managing localized thermal loads generated by focused SR-IR beams.
- Providing stable, highly polished substrates for mounting sensitive AFM/optical components.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
For the first time, infrared spectra on the sub-wavelength scale have been delivered by a synchrotron-radiation-induced thermal expansion technique [Citation1]. The novel experimental result was achieved by coupling an atomic force microscope (AFM) to an infrared (IR) beamline at the UKâs national synchrotron facility, Diamond Light Source. Via broadband synchrotron illumination and an AFM sub-micron tip, molecular IR spectra were obtained by detecting a resonance-enhanced (RE) photothermal signal with spatial resolution beyond the diffraction limit. Together with results on synchrotron IR nanoscopy in scattering mode from the IR beamline at the Advanced Light Source two years ago, the Diamond photothermal nanoprobe approach moves vibrational analysis beyond the diffraction limit and into nanoscale absorption spectroscopy.