EFFECTS OF ADDITIVES IN ELECTROSPRAYING FOR MATERIALS PREPARATION

TiO2 thin films and ZrO2 fine powders were prepared by electrostatic s pray deposition (ESD). The morphology of the thin films and the partic le size of the powders can be varied considerably by adding well-chose n additives to the precursor solutions. Acetic acid (HOAc) and ammonia nitrate (NH4NO3) were used as a solution chemistry modifier and a con ductivity enhancement additive, respectively. It is found that by addi ng HOAc in an alcoholic precursor solution of Ti(OPri)(4), the structu re of the deposited TiO2 films changes from severely cracked to crack- free reticular. In the ZrO2 powder preparation, the particle size of Z rO2 decreases substantially, i.e. from 3.5 mu m down to I mu m upon ad ding NH4NO3 in the precursor solution of zirconium acetylacetonate. Qu antitative analysis of the impedance spectroscopy data of their precur sor solutions has supported this result. (C) 1998 Elsevier Science Lim ited. All rights reserved.