Magnetic properties of the natural and isotope-modified diamond and silicon carbide
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2018-01-01 |
| Journal | EPJ Web of Conferences |
| Authors | Š. Š. Š¢Š°Š»Š“ŠµŠ½ŠŗŠ¾Š², A. V. Inyushkin, E.A. Chistotina, Victor Ralchenko, A. P. Bolshakov |
| Institutions | Kurchatov Institute, Physico-Technical Institute |
| Citations | 5 |
| Analysis | Full AI Review Included |
Technical Documentation and Analysis: Magnetic Properties of Isotope-Modified Diamond
Section titled āTechnical Documentation and Analysis: Magnetic Properties of Isotope-Modified DiamondāExecutive Summary
Section titled āExecutive SummaryāThis research investigates the magnetic properties of synthetic and natural single crystals of diamond and SiC, focusing on the critical role of isotopic modification ($^{12}$C, $^{13}$C). This study validates the superiority of high-purity CVD diamond for advanced electronic and quantum applications.
- Isotopic Impact Confirmed: Study confirms the necessity of high isotopic purity (specifically 99.96% $^{12}$C) to minimize nuclear magnetic moments, a key mechanism for electron spin relaxation.
- Superior CVD Purity: CVD single crystal diamond (SCD) exhibited the lowest concentration of paramagnetic centers ($N_{P}$ < 4 x 1016 cm-3) compared to HPHT and natural diamonds, confirming its highest chemical purity level.
- Methodological Correlation: Paramagnetic center concentration ($N_{P}$) was successfully correlated with free carrier concentration, establishing SQUID magnetometry as a viable method for determining electrically active impurities.
- Fundamental Data: Quantitative data for diamagnetic susceptibility ($\chi_{DIA}$), paramagnetic centers ($N_{P1}, N_{P2}$), and ferromagnetic components ($M_{FM}$) were established for various synthetic SCD recipes.
- Quantum Application Relevance: The low $N_{P}$ and long potential spin diffusion length achieved in isotopically engineered CVD diamond are essential for developing next-generation spin transport and quantum computation devices.
Technical Specifications
Section titled āTechnical SpecificationsāData extracted primarily from Table 2 (Diamond Parameters) and Section 2 (Experimental Details).
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Lowest Paramagnetic Centers ($N_{P2}$) | 4.1 x 1016 | cm-3 | Achieved in Isotope-enriched $^{12}$C Diamond (Sample #6) |
| Typical Diamagnetic Susceptibility ($\chi_{DIA1}$) | 6.0 x 10-6 | emu/mol | High-purity CVD Diamond (Average) |
| Highest Ferromagnetic Component ($M_{FM}$) | 5.0 x 10-4 | emu/g | HPHT Diamond (Sample #3) |
| Measurement Instrument | MPMS XL-7 | SQUID Magnetometer | Used for measuring magnetic moments |
| Measurement Temperature Range | 2 to 300 | K | Covers cryogenic to room temperature analysis |
| Applied Magnetic Field (H) | < 7 | T | Field used for magnetization curves and susceptibility measurements |
| Isotopic Purity (CVD Samples) | 99.96% | $^{12}$C or $^{13}$C | Critical for spin relaxation studies |
| Quantum Number (J) | ~ 1/2 | None | Determined by fitting paramagnetic contribution using Brillouin function |
Key Methodologies
Section titled āKey MethodologiesāThe experimental approach focused on precise synthesis control and highly sensitive cryogenic magnetometry to differentiate magnetic contributions.
- Material Synthesis: High-purity single crystal diamond (SCD) samples were produced using two primary industrial methods: High-Pressure High-Temperature (HPHT) and Microwave Plasma Chemical Vapor Deposition (MPCVD).
- Isotopic Engineering: Specialized CVD growth was utilized to produce monoisotopic diamond, specifically 99.96% enriched in $^{12}$C or 99.96% enriched in $^{13}$C, for direct study of nuclear spin relaxation channels.
- Magnetic Measurement: The static magnetic moments were analyzed using a MPMS XL-7 SQUID magnetometer with a reciprocating sample option (RSO).
- Data Acquisition: Measurements were taken as a function of temperature (2 K < T < 300 K) and magnetic field (H < 7 T) to isolate temperature-dependent paramagnetic and temperature-independent diamagnetic components.
- Susceptibility Analysis: The temperature dependence of molar static susceptibility ($\chi_{M}(T)$) was fitted using the Curie-Weiss law ($\chi_{M}(T) = \chi_{DIA1} + C / (T - \Theta)$) to determine the concentration of paramagnetic centers ($N_{P1}$) and the diamagnetic contribution ($\chi_{DIA1}$).
- Paramagnetic Isolation: The low-temperature paramagnetic contribution was isolated by calculating the difference in magnetization $\Delta M(T_{1}, T_{2}) = M(T_{1}, H) - M(T_{2}, H)$ and fitted using the Brillouin function $B_{J}(x)$ to determine the precise concentration ($N_{P2}$) and quantum number ($J$).
6CCVD Solutions & Capabilities
Section titled ā6CCVD Solutions & CapabilitiesāThe findings underscore the immediate need for ultra-high purity, isotopically controlled diamond synthesized via MPCVDāprecisely the core expertise of 6ccvd.com. Our capabilities exceed the material requirements cited in this foundational research, enabling direct commercialization and scaling of these critical materials.
| Requirement (From Paper) | 6CCVD Solution & Capability | Technical Advantage for Researchers/Engineers |
|---|---|---|
| Material 1: High-Purity SCD for Spin Transport (Low $N_{P}$, Sample #6) | Optical/Electronic Grade Single Crystal Diamond (SCD) | Our MPCVD process consistently yields SCD with extremely low intrinsic defect densities, replicating and exceeding the purity of Sample #6 ($N_{P}$ as low as 4 x 1016 cm-3). |
| Material 2: Isotopically Engineered Substrates ($^{12}$C / $^{13}$C Purity) | Custom Isotopic Diamond | 6CCVD offers synthesis of SCD with tailored isotopic ratios (e.g., >99.99% $^{12}$C). This is crucial for maximizing the electron spin relaxation time (T2) required for quantum memory and sensing applications. |
| Scaling & Dimensions (Transition from small crystals to wafers) | Large Area Single Crystal Plates & PCD Wafers | We offer SCD/PCD material in custom dimensions up to 125mm in diameter, facilitating the move from research samples to scalable device prototypes and industrial wafers. |
| Surface Finish & Defect Control (Implied requirement for high-end research) | Ultra-Precision Polishing (SCD Ra < 1 nm) | Our proprietary polishing methods provide atomically smooth surfaces, minimizing external defect creation and surface scattering that could interfere with sensitive magnetic measurements or device integration. |
| Integration and Contacts (Future device requirement) | Custom Metalization Services (Au, Pt, Pd, Ti, W, Cu) | To support functional magnetic or electronic devices, 6CCVD performs internal metalization, ensuring high-quality ohmic or Schottky contacts on diamond substrates. |
| Doping Studies (SiC samples used free carriers $n \sim 10^{18}$ cm-3) | Boron-Doped Diamond (BDD) | For extending paramagnetic correlation studies into conductive materials, we provide SCD and PCD doped with Boron across a wide range of concentrations (up to 1021 cm-3). |
| Technical Consulting (Complexity of defect analysis) | In-House PhD Engineering Support | Our technical team specializes in defect management and material optimization for spin-related physics, providing critical insight for replicating or extending this research into specific applications (e.g., NV centers, solid-state magnetometry). |
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
The magnetic properties of single crystals of synthetic diamond and crystals of silicon carbide were studied. High-purity samples of diamonds synthesized with HPHT and CVD technologies were used. The crystals of silicon carbide were grown by sublimation and industrial technology. Along with samples with a natural isotopic composition, monoisotopic crystals of diamond (99.96% 12 C and 99.96% 13 C) and silicon carbide (99.993% of 28 Si) were studied. On the basis of the data obtained, the diamagnetic susceptibility was determined and the concentration of paramagnetic centers and the content of the ferromagnetic component were evaluated. The results are discussed.