Naslov
Efficiency of dynamical decoupling using constant time CPMG experiment in two different model systems

Autori
Jurec, Jurica ; You, Jiangyang ; Rakvin, Boris ; Jokić, Milan ; Carić, Dejana ; Ilakovac-Kveder, Marina

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
PETER Summer School

Mjesto i datum
Brno, Češka Republika, 03.10.2018. - 05.10.2018

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
ethanol ; trehalose ; CPMG pulse sequence ; dynamical decoupling

Sažetak
Constant time Carr-Purcell-Meiboom-Gill (CPMG) pulse sequences were applied to two systems, ethanol doped with nitroxyl radical TEMPO and gamma-irradiated trehalose. The aim was to investigate the effect of different electron spin relaxation mechanisms in different systems on the efficiency of the preservation of the phase memory relaxation time T_m by dynamical decoupling and to test whether CPMG sequences can be used to discriminate them. In the case of ethanol, paramagnetic nitroxyl radical TEMPO was applied in the concentration range 0.2-1.1 mM. Trehalose samples were irradiated using X- ray radiation with standard dosages of 5-10 kGy. For both model systems, the measurements on glassy and crystalline type of samples were conducted to investigate impact of disorder as well. For ethanol no dependence of T_m on the concentration of paramagnetic centres and on the length of the used refocusing pulses was observed, implying nuclear spectral diffusion (NSD) as the dominant mechanism of electron spin decoherence [1]. Contrary to the observations in ethanol, no stretched exponential decay was observed when determining T_m in trehalose. In ethanol there was linear increase of T_m with number n of used refocusing pulses in the CPMG sequence. In trehalose the increase of T_m with n was not linear, the saturation effects observed for n≥4, which suggests that NSD isn’t the dominant mechanism of electron spin decoherence. The impact of instantaneous diffusion (ID) in trehalose is supported by the calculation of the concentration of radicals [2]. In conclusion, the efficiency of dynamical decoupling using constant time CPMG experiment strongly depends on the dominant mechanism of electron spin decoherence, therefore it can be used to determine whether NSD or ID is the dominant mechanism of decoherence.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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