Combinatorial synthesis of oxide powders with an autopipetting system

We describe development of a relatively simple, rapid route to produce combinatorial compositional oxide powder libraries by autopipetting of liquid precursors. This partitioning approach should apply equally well to any low viscosity, liquid precursors for the synthesis of oxide powders. A commercial autopipet is modified by fitting a plastic "mask" assembly beneath the pipet array in order to partition and direct liquids into crucibles. A series of 10 mixtures from two precursor solutions can be produced quickly. After they are dispensed, the liquid mixtures are dried in the crucibles and reacted at elevated temperatures to produce oxide powders. In the present work, the viability of the pipetting process is demonstrated by using a polymerizable complex powder synthesis method to produce (1-x) LaAlO(3) - x SrTiO(3) powders. For this system, a reaction at 900 degrees C for 2 h in air was sufficient to yield solid solutions in this system. X-ray powder diffraction was used to determine the pseudocubic unit cell lattice parameter. The linear change of lattice constant with composition confirms the compositional accuracy of the partitioning.