NMR OF HE-3 IN POROUS GLASSES

A study of He-3 in porous glasses is performed in which the observed c hemical shifts and lineshapes are attributed to the local magnetic fie ld distribution in the pores and to the distribution of pore shapes. T he observed relaxation times T-1 and T-2 are explained by the residual oxygen concentration in the pores and by the diffusion of He-3 in the inhomogeneous local field, respectively. The study indicates that in principle sample tubes containing He-3 in the pores as a built-in lock substance could be produced but the production is not straightforward . He-3 proves to be an ideal nucleus for studying the shape of void st ructures in solids. (C) 1996 Academic Press, Inc.