Electron spin decoherence as a measure of nuclear spin bath frustration

Two realisations of solid-state environment, which differ in molecular packing, glassy and crystalline solid ethanol, are used as a model systems to study disorder in terms of nuclear spin bath frustration. It is probed by the hyperfine interaction of the electron spin from the incorporated paramagnetic nitroxyl radical TEMPO. Nuclear spectral diffusion from ethanol protons is presented as the dominant mechanism of electron spin decoherence and proposed as a descriptor of the extent of disorder present in the system. It is shown that the dynamical decoupling control of the electron spin is affected by the extent of disorder in terms of the heterospin dephasing and can be numerically evaluated for the specific model system. The effect of odd/even number of decoupling pulses was not observed suggesting that for the description of proton spin bath frustration in solid ethanol higher terms than fourth-order proton spin correlations might be considered in modelling spectral diffusion mechanism.