Two-dimensional NMR separation of inhomogeneous from from homogeneous lineshapes in the glassy state. 87Rb in a proton glass DRADP

Abstract

In systems with a glassy type of disorder NMR absorption lines are strongly inhomogeneously broadened, thus completely masking the shape of a homogeneous line. A two-dimensional NMR technique is capable of showing in one frequency domain the inhomogeneous frequency distribution characteristic of a glassy disorder, which is static on the NMR timescale, whereas in the second frequency domain the undistorted homogeneous lineshape appears. The inhomogeneous lineshape is a convolution of the frequency distribution function f(ν), which is known theoretically for different types of glasses, and the homogeneous lineshape. The 2D technique thus makes it possible to obtain the experimental f(ν) via a deconvolution of the inhomogeneous lineshape with the homogeneous one.