Logo Logo
Help
Contact
Switch Language to German
Jardon-Alvarez, Daniel; Guenne, Jörn Schmedt Auf Der (2018): Reduction of the temperature gradients in laser assisted high temperature MAS NMR. In: Solid State Nuclear Magnetic Resonance, Vol. 94: pp. 26-30
Full text not available from 'Open Access LMU'.

Abstract

Laser assisted magic angle spinning (MM) solid state NMR experiments enable studying physicochemical properties at very high temperatures with high resolution. Large temperature gradients however, can degrade resolution and precision of this technique. Due to the strong temperature dependence of the Pb-207 chemical-shift in lead nitrate, a temperature difference along the sample leads to a broadening of the signal. A second moment analysis of the NMR spectra serves as an analytical method to quantify the temperature gradient. We show how an arbitrary line-shape can be decomposed into a set of Gaussian functions from which the 2nd moment is calculated in an analytical fashion which improves the numerical stability of the analysis. It was found that measuring the FID in a non-steady temperature state can reduce the temperature gradient inside the rotor, caused by the single-sided heating.