Microscopic and structural study on the formation of mechanochemical synthesized BaTiO3 and ZnTiO3 perovskites

Abstract

In this work, the properties of mechanochemically produced (by using mills made from different materials) barium-titanate (BaTiO3) and zinc-titanate (ZnTiO3) perovskites are compared. Mechanochemistry is a process that can cover the energy demand of some reaction pathways between solid materials. This process is called “high-energy milling”, for which not all types of mills are suitable. In our case, a planetary ball mill provided the necessary energy. Using a model, the required energy is determinable; the energy released during an impact of a milling ball (E b – ball-impact energy), as well as during the whole milling (E cum – cumulative milling energy). Thus, a milling-energy map was created, with which the applied E b and E cum values were visualized depending on the different grinding parameters. The parameters changed were the material of the grinding vessels, the number of grinding balls, and the rotational speed. The transformation was tracked by X-ray diffraction (XRD) measurements, and electron microscopic images (TEM and SEM) of the perovskites produced were taken. This study aimed to draw conclusions that will help later in the synthesis of materials with other perovskite structures by choosing optimal milling parameters.