The role of stress in nucleus development during dehydration of certain alums

Abstract

Microscopic examination of dehydration nuclei developed on cleaved faces {111} of potassium alum and a mixed K(Al, Cr) alum revealed a characteristic progressive sequence of surface textural changes and crack propagation before and during the initiation and growth of the product phase; these surface modifications are interpreted as evidence that local stresses may be a more important contributory factor in nucleation than has hitherto been recognized.