High-sensitivity Q-band electron spin resonance imaging system with submicron resolution

Area of Science:

• Physics
• Chemistry
• Materials Science

Background:

• Electron Spin Resonance (ESR) is a powerful spectroscopic technique.
• Microimaging requires high spatial resolution and sensitivity.
• Q-band ESR offers specific advantages for certain applications.

Purpose of the Study:

• To develop and present a novel pulsed ESR microimaging system operating at Q-band frequencies.
• To achieve high spatial resolution and sensitivity for microimaging applications.
• To demonstrate the system's capability for diverse sample types.

Main Methods:

• Development of a pulsed ESR spectrometer.
• Integration of high-performance gradient drivers (up to 94 A).
• Design of a unique, high-sensitivity imaging probe (1.6 × 10^8 spins/√Hz).

Main Results:

• Achieved spatial resolutions down to ~440 nm for solid samples and ~6.7 µm for liquid samples.
• Demonstrated high spin sensitivity (~2.7 × 10^6 spins for 1-hour acquisition).
• System operates effectively with high gradient strengths and durations.

Conclusions:

• The developed Q-band pulsed ESR microimaging system offers unprecedented resolution and sensitivity.
• Potential applications include imaging point defects in semiconductors and measuring oxygen in biological samples.
• This technology advances nanoscale imaging capabilities in ESR spectroscopy.