Diamond rotors for high magic angle spinning frequencies

Area of Science:

• Solid-state Nuclear Magnetic Resonance (NMR) Spectroscopy
• Materials Science
• Biophysics

Background:

• Magic Angle Spinning (MAS) NMR spectroscopy's resolution is limited by rotor spinning frequencies.
• Traditional yttria-stabilized zirconia (YSZ) rotors have mechanical constraints limiting spinning frequencies to ~110 kHz.
• Higher frequencies (>300 kHz) are theoretically required for resolution comparable to solution NMR.

Purpose of the Study:

• To develop advanced diamond rotors for MAS NMR to achieve higher spinning frequencies.
• To improve rotor fabrication techniques for enhanced concentricity and spinning stability.
• To evaluate diamond rotor performance and usability for biological and material science applications.

Main Methods:

• Fabrication of diamond rotors using high-precision lathe and laser machining.
• Testing rotor compatibility with Bruker MAS 3 spinning systems.
• Evaluation of chemical vapor deposition (CVD) versus high-pressure high-temperature (HPHT) diamond materials.
• 3D-printed tools for efficient rotor repacking.
• Spin stability tests and multidimensional NMR of Aβ1-40.

Main Results:

• Developed diamond rotors with improved concentricity and spinning stability.
• Diamond rotors demonstrated compatibility and performance comparable to or exceeding commercial rotors.
• HPHT diamond material was found to be preferable over CVD diamond.
• Demonstrated robustness and usability through extended spin tests and NMR spectra.

Conclusions:

• Advanced diamond rotor fabrication significantly enhances MAS NMR capabilities.
• These rotors enable higher spinning frequencies, crucial for improved spectral resolution.
• The developed technology paves the way for future advancements in MAS NMR for diverse scientific fields.