The aim was to study formulations containing aluminosilicate and alumina in order to obtain compositions with suitable properties to fabricate dielectric ceramic devices. Initially, the precursors were subjected to chemical, mineralogical and granulometric characterization. The formulations were defined and specimens were pressed (19.6 MPa) in shapes of disc and rectangular bar. Specimens were dried, heat-treated at 1400, 1450 and 1500 °C and the mineralogical, morphological, physical, dielectric and mechanical properties were evaluated. The relative dielectric constant (εr) and loss tangent (tanδ) were evaluated at 0.1, 1, 10 and 100 kHz at room temperature. The mullite was the major phase for the studied temperature range. Compositions with a higher content of fluxes showed lower porosity and better dielectric properties and flexural strength. Values of εr at 1 kHz (~3.5 to 4.5) were close to that of the mullite for the samples fired at 1400 °C.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.