Mechanoluminescence from piezoelectric crystals of an europium complex

Mechanoluminescence (ML) from crystals of an europium complex was investiga ted by microphotography. Crystals prepared by recrystallization from aceton e solution are noncentrosymmetric, piezoelectric ones. We have succeeded in catching the images of ML occurring at the moment of cleaving these crysta ls along their axis. From these ML images, we understand that the formation of piezoelectric charges is one of the most important processes for ML exc itation. (C) 2000 Elsevier Science S.A. All rights reserved.