Battelle Memorial Institute

Peter J Melling

Scott Lawrence Swartz

Roy F Wielonski

Beebhas C Mutsuddy

Ibrahim Sekercioglu

Wha J Kim

David T Hayhurst

A method for producing a thin film of a ferroelectric perovskite material having the steps of providing a first substrate; depositing a first layer of a sol-gel perovskite precursor material wherein the crystallization of this precursor material to the pervoskite phase is insensitive to the first substrate; depositing a second layer of a sol-gel perovskite precursor material wherein the crystallization is sensitive to the first substrate; and heat-treating the deposited layers to form ferroelectric perovskites. A heat treatment step to form perovskites may optionally follow the deposition of the first layer. The first layer of sol-gel perovskite precursor material is selected to produce a perovskite upon heat treatment of: lead titanate (PbTiO.sub.3), or strontium titanate (SrTiO.sub.3). The second layer of sol-gel perovskite precursor material is selected to produce a perovskite upon heat treatment of: lead zirconate titanate (Pb(Zr,Ti)O.sub.3), lead zirconate (PbZrO.sub.3), lead lanthanum titanate ((Pb,La)TiO.sub.3), lead lanthanum zirconate ((Pb,La)ZrO.sub.3), lead lanthanum zirconate titanate ((Pb,La)(Zr,Ti)O.sub.3), lead magnesium niobate (Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3), lead zinc niobate (Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3), barium titanate (BaTiO.sub.3), strontium barium titanate ((Sr,Ba)TiO.sub.3), barium titanate zirconate (Ba(Ti,Zr)O.sub.3), potassium niobate (KNbO.sub.3), potassium tantalate (KTaO.sub.3), or potassium tantalate niobate (K(Ta,Nb)O.sub.3).

Process for making sol-gel deposited ferroelectric thin films

Crystallization in a force field

Process for producing high purity aluminum nitride powder by reacting aluminum sulfide with gaseous ammonia at an intermediate temperature (about 700.degree. C.) and holding at that temperature until an intermediate product (Al.sub.x N.sub.y S.sub.z) is formed where x, y, and z are integers; then further heating to a temperature above 1100.degree. C. and reacting with gaseous ammonia. A high purity, low oxygen containing, free flowing powder is produced. A posttreatment using a carbon source such as graphite further reduces the oxygen content. The oxygen content can be further reduced by reacting the aluminum nitride formed with carbon at about 1600.degree. C.

Process for preparing high purity aluminum nitride

A process for curing and densifying a sol-gel derived inorganic thin film at lower temperatures (between 10.degree. C. and 400.degree. C.) by applying the films to a substrate, drying the film at a low temperature, exposing the film to a low pressure plasma. The film may be an oxide (e.g. SiO.sub.2), nitride (e.g. Si.sub.3 N.sub.4), oxynitride (e.g. SiO.sub.x N.sub.y) or sulfide (e.g. GeS.sub.2).

Process for low temperature curing of sol-gel thin films

Growing community of inventors

Worthington, OH, United States of America

Peter J Melling