Experimental studies of the influence of defects and impurities on structural phase transitions

A review of experiments pertaining to the influence of defects and impurities on structural phase transitions is given. The systems covered are the KH 2 P0 4 -family, the TGS-family, the SrTiO 3 -family and, finally, the K 1-x (Li, Na) x TaO 3 -system. Emphasis is placed on the influences of impurities and defects on static and dynamic critical and precritical effects, as well as their ability to induce glass-like precursor effects.