Chan, J.
, Feb-Ayala, W.
, Rotter, L.
, Levin, I.
and Geyer, R.
(2021),
Solidus Phase Relationships in the AO-Al<sub>2</sub>O<sub>3</sub>-Nb<sub>2</sub>O<sub>5</sub> (A = Ca, Sr) Systems, Solidus Phase Relationships in the AO-Al<sub>2</sub>O<sub>3</sub>-Nb<sub>2</sub>O<sub>5</sub> (A = Ca, Sr) Systems
(Accessed May 4, 2024)
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Solidus Phase Relationships in the AO-Al2O3-Nb2O5 (A = Ca, Sr) Systems
Published
Author(s)
Julia Y. Chan, Wilma Feb-Ayala, , ,
Abstract
Dielectric ceramics for wireless communications exhibiting modest permittivity, high quality factor (Q), and near-zero temperature coefficient are needed for high frequency, high power applications. Efforts are in progress to replace Ta2O5-based ceramics with less costly oxides that exhibit similar properties. Phase equilibria relations in the CaO-Al2O3-Nb2O5 and SrO-Al2O3-Nb2O5 systems have been determined at 1350 degrees C to 1525 degrees C in air. Phase assemblages were determined by x-ray powder diffraction methods at room temperature. The existence of the double perovskites, A2AlNbO6 (A = Ca, Sr), were confirmed in both ternary systems. In the SrO-Al2O3-Nb2O5 system, a previously unreported ternary phase was found to occur between Sr2AlNbO6 and SrO. A series of cryolite-type solid solutions, Sr3(Sr1-xNb2-x)O9-3/2x (O < x < 0.5), will also be described. The results of dielectric property measurements in the two systems will be presented.Citation
Solidus Phase Relationships in the AO-Al<sub>2</sub>O<sub>3</sub>-Nb<sub>2</sub>O<sub>5</sub> (A = Ca, Sr) Systems
Pub Type
Others
Keywords
microwave dielectric, oxides, properties phase equlibria, structure
Citation
Created October 12, 2021