Effect of temperature on cleavage mechanoluminescence of organic and inorganic crystals

The effect of temperature on the mechanoluminescence (ML) of organic and in organic crystals, produced during their cleavage is reported. The peak of M L intensity I-m and total ML intensity I-T decrease with increasing tempera ture of the crystals and tend to disappear beyond a particular temperature. No detectable change in time corresponding to peak of ML intensity is foun d with increasing temperature of the crystals. Generally the ML of piezoele ctric crystals ceases near their melting point, however, it disappears in n on-piezoelectric crystals much below their melting points. The decrease of ML efficiency with temperature should involve both, the change in crystal p roperties with temperature and the usual decrease in quantum yield caused b y the increased radiationless transition.