Probing the Structure and Crystallinity of a Lithium Silicate Glass by ²⁹Si Magic‐Angle‐Spinning NMR Spectroscopy

The short‐range order in noncrystalline and crystalline silicates can be investigated with 29 Si magic‐angle‐spinning (MAS) NMR spectroscopy. Different 29 Si chemical shifts are observed depending on the degree of cross‐linkage of the silicate, the SiOSi bond angles, and the interatomic distances. In this way, the distribution of SiOSi angles in glasses, the crystallinity of which lies between 0 and 100%, can be obtained.