Motional Narrowing: Ask an NMR Expert

[Baggio]

Hi,

I'm hoping there are some NMR'ers around to answer this question, I Just want to understand the jist of what motional narrowing is. I'm looking to apply this to a solid state system.

thanks

 

[JeffKoch]

Are you referring to Dicke narrowing? That as I understand it results from velocity-changing collisions (that don't affect the internal state of the radiator) increasing the time it takes for a radiating atom (or nucleus) to move a straight-line distance equal to the wavelength of emission. If the mean free path between such collisions is less than the wavelength, the line is said to be Dicke narrowed. I can't really understand it except through correlation functions and Fourier transforms that yield spectral line profiles. Perhaps that means I don't fully understand it.