Method of making mixed metal oxide ceramics
AssigneeDrexel University
InventorsWei-Heng Shih, Huiming Gu, Wan Y. Shih
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Abstract
A method of making dielectric ceramics containing mixed metal oxides is provided. The method comprises the steps of at least partially coating a metal oxide powder with a metal hydroxide or metal oxide, compacting the coated powder with one or more additional metal compounds or metal compound precursors, and directly sintering the compact in a single step. The method of the invention may be used to avoid occurrence of significant quantities of one or more undesired but thermodynamically or kinetically favored side products. The method of the invention may also be used to synthesize perovskites, in particular lead-magnesium-niobium (PMN), lead-magnesium-niobium-lead-titanium (PMN-PT) perovskites, or lead zirconate titanate (PZT).
Claims19
A method of making a ceramic composition comprising a mixed metal compound, said method comprising the steps of:
- a. providing a coated metal oxide powder, wherein the coating comprises a metal hydroxide compound containing a first metal;
- b. compacting said coated metal oxide powder with one or more metal compounds or metal compound precursors selected from the group consisting of PbO, 3Pb(NO3)2.7PbO, Pb(NO3)2, PbCO3, (PbCO3)2Pb(OH)2, Pb(OH)2 and PbTiO3, to form a body;
- and
- c. heating said body from step (b) comprising said coated metal oxide powder and said one or more metal compounds or metal compound precursors selected from the group consisting of PbO, 3Pb(NO3)2.7PbO, Pb(NO3)2, PbCO3, (PbCO3)2Pb(OH)2, Pb(OH)2 and PbTiO3, to form a ceramic composition comprising a substantially pure perovskite phase of a mixed metal compound.
Dependencies are inferred from the claim text.