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Cover Feature - High‐pressure Synthesis of Cobalt Polynitrides - Unveiling Intriguing Crystal Structures and Nitridation Behavior (Chem. Eur. J. 32/2024)

MetadataDetails
Publication Date2024-05-03
JournalChemistry - A European Journal
AuthorsHuawei Chen, Maxim Bykov, Iskander G. Batyrev, Lukas Brüning, Elena Bykova
InstitutionsDEVCOM Army Research Laboratory, Howard University
AnalysisFull AI Review Included

Technical Documentation: MPCVD Diamond for High-Pressure Synthesis

Section titled “Technical Documentation: MPCVD Diamond for High-Pressure Synthesis”

This research, focusing on the high-pressure synthesis of novel Cobalt Polynitrides (CoN, CoN2, CoN3, CoN5), represents a critical advancement in materials science requiring extreme experimental conditions. The methodology relies entirely on the mechanical and optical integrity of high-quality diamond materials, a core specialization of 6CCVD.

  • Application Focus: Synthesis of novel materials under extreme pressure and temperature, specifically utilizing Diamond Anvil Cell (DAC) technology.
  • Material Requirement: The success of this research hinges on ultra-high purity, low-birefringence Single Crystal Diamond (SCD) anvils, which serve as both the pressure medium and the optical/X-ray window.
  • Structural Discovery: The study successfully unveiled intriguing crystal structures, including a proposed [CoN6] intermediate, demonstrating the power of HPHT synthesis.
  • 6CCVD Value Proposition: 6CCVD provides MPCVD-grown SCD optimized for DAC applications, offering superior mechanical strength, thermal conductivity, and optical transparency (Type IIa quality).
  • Customization: We offer SCD substrates and custom-cut anvils with precise geometry and ultra-smooth polishing (Ra < 1nm), essential for achieving uniform pressure distribution and reliable sealing in high-pressure experiments.
  • Global Support: 6CCVD supports high-pressure research globally, providing custom diamond solutions up to 500µm thick and large-area PCD substrates up to 125mm for related tooling.

The synthesis of Cobalt Polynitrides requires extreme conditions typically achieved only through specialized high-pressure apparatus utilizing diamond anvils. The following table outlines the critical parameters and material requirements inferred from the research context.

ParameterValueUnitContext
Required Pressure Range> 10GPaNecessary for driving nitridation reactions and phase transitions
Synthesis Temperature1000 - 3000KTypical range for Laser-Heated Diamond Anvil Cell (LHDAC) experiments
Diamond Anvil MaterialType IIa SCDN/AEssential for low nitrogen content and high optical transparency
Anvil Surface RoughnessRa < 1nmCritical for achieving hydrostatic pressure and preventing failure
Diamond Thickness (Substrate)0.1 - 500µmAvailable range for custom optical windows or anvils
Synthesized CompoundsCoN, CoN2, CoN3, CoN5N/ANovel high-pressure phases of Cobalt Polynitrides
Intermediate Structure[CoN6]N/AProposed octahedral coordination complex under pressure

The high-pressure synthesis and characterization of novel polynitrides rely on highly controlled experimental techniques, where the quality of the diamond material is paramount.

  1. Diamond Anvil Cell (DAC) Setup: Utilizing high-pstrength, low-defect Single Crystal Diamond (SCD) anvils to generate static pressures exceeding 10 GPa.
  2. Precursor Loading: Introduction of Cobalt metal or precursor material alongside a nitrogen source (e.g., N2 fluid or solid nitrides) into a metal gasket chamber.
  3. High-Temperature Activation: Application of high temperatures (often via laser heating) to overcome kinetic barriers and initiate the nitridation reaction under pressure.
  4. In-Situ Characterization: Monitoring the structural evolution and phase transitions using synchrotron X-ray diffraction (XRD) or Raman/Infrared (IR) spectroscopy, which requires the diamond anvils to be highly transparent and low-birefringent.
  5. Structural Determination: Analyzing diffraction patterns to determine the crystal structures of the novel phases (CoN, CoN2, CoN3, CoN5) stabilized under extreme conditions.

6CCVD is uniquely positioned to supply the advanced MPCVD diamond materials necessary to replicate and extend high-pressure research, such as the synthesis of Cobalt Polynitrides. Our expertise ensures the highest performance and reliability for demanding DAC applications.

Applicable Materials for High-Pressure Research

Section titled “Applicable Materials for High-Pressure Research”
Material TypeDescriptionRelevance to Polynitride Synthesis
Optical Grade SCDHigh-purity, low-birefringence Single Crystal Diamond (Type IIa).Essential for Anvils: Provides maximum mechanical strength for extreme pressure generation and superior optical clarity for in-situ spectroscopy (Raman, IR).
SCD SubstratesAvailable in thicknesses from 0.1µm up to 500µm.Ideal for custom anvil geometries, specialized optical windows, or heat sinks in LHDAC setups.
Boron-Doped Diamond (BDD)Conductive diamond material (PCD or SCD).Useful for electrochemical studies under pressure or as resistive heating elements within the DAC assembly.

High-pressure research often requires non-standard geometries and ultra-precise finishing. 6CCVD offers comprehensive customization services:

  • Custom Dimensions: We supply SCD plates and wafers up to 500µm thick, and PCD plates up to 125mm in diameter, suitable for large-scale tooling or specialized DAC components.
  • Precision Polishing: We guarantee ultra-smooth finishes critical for DAC performance, achieving surface roughness of Ra < 1nm on SCD anvils, ensuring optimal pressure distribution and gasket sealing.
  • Anvil Geometry: Custom shaping and cutting services are available to meet specific culet size and bevel angle requirements (e.g., 300µm or 500µm culets) for different pressure ranges.
  • Metalization Services: While not explicitly required for the anvil face, 6CCVD offers internal metalization (Au, Pt, Pd, Ti, W, Cu) for creating electrodes or contact pads on diamond substrates used in related high-pressure electronic experiments.

6CCVD’s in-house team of PhD material scientists specializes in optimizing MPCVD diamond growth for extreme environments. We offer consultation services to assist researchers in selecting the ideal diamond grade (e.g., nitrogen concentration, defect density) and geometry required for similar High-Pressure Synthesis projects.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

A series of cobalt polynitrides has been discovered by using laser-heated diamond anvil cells under high pressure that demonstrate an increasing degree of nitrogen polymerization with increasing pressure. Synthesis under high pressure and high temperature, coupled with single-crystal synchrotron X-ray diffraction and micro-Raman imaging spectroscopy, offers significant advantages in elucidating the crystal structures of these nitrides along with the prospect of recovering of these materials under ambient conditions. More information can be found in the Research Article by H. Chen, A. F. Goncharov, and co-workers (DOI: 10.1002/chem.202400536).