Study on the Relation of Lattice Constant Dependence on the Grain Size in Some Nanocrystallites of Perovskite Structures

Abstract

The influence of grain size on the lattice constant in some nanocrystallites of perovskite structure was studied in experiment. Some nanometer ultra fine particles of CaMnO3, Nd0.67Sr0.33MnO3 and Nd0.67Sr0.33Mn0.9Cu0.1O3 were prepared by sol-gel method, which were characterized by XRD, thus phase compositions, lattice constants and grain sizes could be obtained. It was found that their lattice constants all decreased with the decreasing grain sizes. In the end, this phenomenon were explained by the binding energy theory.