Sub-Solidus Synthesis and Microwave Dielectric Characterization of Plagioclase Feldspars
Abstract:NaxCa1−xAl2−xSi2+xO8 plagioclase solid solutions (0≤x≤1) were synthesized under sub-solidus conditions using a solid-state reaction technique. The plagioclase formation and the sintering temperature decreased with an increase in x from the anorthite (CaAl2Si2O8; x=0) to the albite (NaAlSi3O8; x=1).
Microwave (MW) dielectric measurements revealed that slow-cooled (P 1) anorthite exhibited higher Q×f values than fast-cooled (I 1) anorthite. Slow cooling also considerably improved the Q×f values of the sodium-rich NaxCa1−xAl2−xSi2+xO8 solid solutions (0.8≤x≤1), where the highest Q×f value of 17 600 GHz was obtained for slow-cooled Na0.8Ca0.2Al1.2Si2.8O8. The temperature coefficient of resonant frequency (f) approached zero for 0.8≤x≤1.
Document Type: Research Article
Affiliations: Advanced Materials Department, Jozef Stefan Institute, 1000 Ljubljana, Slovenia
Publication date: 2005-09-01