Kemp, Thomas F. and Balakrishnan, G. and Pike, Kevin J. and Smith, Mark E. and Dupree, Ray (2010) Thermometers for low temperature Magic Angle Spinning NMR. Journal of Magnetic Resonance, 204 (1). pp. 169-172.Full text not available from this repository.
The measurement of temperature in a Magic Angle Spinning NMR probe in the temperature range 85-300 K is discussed. It is shown that the shift of the Sn-119 resonance of Sm2Sn2O7 makes a good thermometer with shift being given by delta = 223 - 9.54 x 10(4)/T ppm and a potential precision of better than 0.5 K over the entire temperature range. The sensitivity is such (e.g. 4.2 ppm/K at 150 K) that small temperature gradients across the sample can readily be measured. Furthermore, since the spin-lattice relaxation time is very short, measurements can be made in similar to 1 s enabling relatively rapid temperature changes to be followed. Values for the chemical shift of Pb-207 in Pb(NO3)(2) down to similar to 85 K are also presented. Although the Pb-207 shift variation is approximately linear near room temperature (we find a slope 0.725 +/- 0.002 ppm/K over the range 293-153 K), it clearly deviates from linearity below similar to 130 K.
|Journal or Publication Title:||Journal of Magnetic Resonance|
|Uncontrolled Keywords:||Solid-state NMR ; Magic Angle Spinning ; Low temperature ; Thermometers|
|Deposited On:||27 Feb 2012 16:16|
|Last Modified:||26 Jul 2012 20:09|
Actions (login required)