Pulsed three-dimensional electron spin resonance microscopy.

A three-dimensional (3D) electron spin resonance (ESR) microimaging system, operating in pulse mode at 9 GHz is presented. This microscope enables the acquisition of spatially resolved magnetic resonance signals of free-radicals in solid or liquid samples with a resolution of up to ∼3.5×7×11.4 μm in 20 min of acquisition. The detection sensitivity at room temperature is ∼1.2×109 spins/[Square_Root]Hz, which enables the measurement of ∼2×107 spins in each voxel after 60 min of acquisition. The resolution and detection sensitivity are the best obtained so far for ESR at ambient conditions of temperature and pressure. This ESR microscope can be employed in the investigation of a variety of samples in the fields of botany, life sciences, and materials science. [ABSTRACT FROM AUTHOR]