Title :
Crystal structure and microwave dielectric properties of ATiO3, ATa2O6, AWO4 (A = Ni, Mg, Co) ceramics
Author :
Kim, Eung Soo ; Jeon, Chang Jun
Author_Institution :
Dept. of Mater. Eng., Kyonggi Univ., Suwon, South Korea
Abstract :
Microwave dielectric properties of ATiO3, ATa2O6 and AWO4 (A = Ni, Mg, Co) ceramics were investigated based on the structural characteristics of oxygen octahedra. ATiO3 (trigonal ilmenite), ATa2O6 (tetragonal tri-rutile) and AWO4 (monoclinic wolframite) ceramics have A- and B-site oxygen octahedra with the different sharing type. Quality factor (Qf) of the specimens was affected by the sharing types of oxygen octahedra. The temperature coefficient of resonant frequency (TCF) of the specimens was decreased with increasing of octahedral distortion per molar volume. The dielectric constant (K) of the specimens was dependent on the dielectric polarizabilities and cations bond valence between octahedral cations and oxygen ion.
Keywords :
bonds (chemical); ceramics; cobalt compounds; crystal structure; dielectric materials; dielectric polarisation; magnesium compounds; microwave materials; nickel compounds; permittivity; CoTa2O6; CoTiO3; CoWO4; MgTa2O6; MgTiO3; MgWO4; NiTa2O6; NiTiO3; NiWO4; cation bond valence; crystal structure; dielectric constant; dielectric polarizability; microwave dielectric property; monoclinic wolframite ceramics; quality factor; resonant frequency; temperature coefficient; tetragonal trirutile ceramics; trigonal ilmenite ceramics; Bonding; Ceramics; Crystalline materials; Dielectric constant; Dielectric materials; Microwave devices; Powders; Q factor; Temperature; Titanium compounds;
Conference_Titel :
Applications of Ferroelectrics, 2009. ISAF 2009. 18th IEEE International Symposium on the
Conference_Location :
Xian
Print_ISBN :
978-1-4244-4970-5
Electronic_ISBN :
1099-4734
DOI :
10.1109/ISAF.2009.5307567
