Distance measurement between trityl radicals by pulse dressed electron paramagnetic resonance with phase modulation.

ABSTRACT: Distance measurement in the nanometre range is among the most important applications of pulse electron paramagnetic resonance today, especially in biological applications. The longest distance that can be measured by all presently used pulse sequences is determined by the phase memory time Tm of the observed spins. Here we show that one can measure the dipolar coupling during strong microwave irradiation by using an appropriate frequency- or phase-modulation scheme, i.e. by applying pulse sequences in the nutating frame. This decouples the electron spins from the surrounding nuclear spins and thus leads to significantly longer relaxation times of the microwave-dressed spins (i.e. the rotating frame relaxation times T1ρ and T2ρ) compared to Tm. The electron-electron dipolar co

SUBMITTER: Wili N 

PROVIDER: S-EPMC10500722 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature