Dielectric Properties of the "Twinned" 8H-Hexagonal Perovskite Ba8Nb4Ti3O24 |
| |
| Authors: | Ritesh Rawal Antonio Feteira Alberto Arenas Flores Neil C Hyatt Anthony R West Derek C Sinclair Kumaravinothan Sarma Neil McN Alford |
| |
| Affiliation: | Department of Engineering Materials, University of Sheffield, Sheffield S1 3JD, U.K.; Physical Electronics and Materials, London South Bank University, London SE1 0AA, U.K. |
| |
| Abstract: | The dielectric properties of dense ceramics of the "twinned" 8H-hexagonal perovskite Ba8Nb4Ti3O24 are reported. Single-phase powders were obtained from the mixed-oxide route at 1325°C and ceramics (>92% of the theoretical X-ray density) by sintering in air or flowing O2 at 1400°–1450°C. The ceramics are dc insulators with a band gap >3.4 eV that resonate at microwave frequencies with relative permittivity, ?r～44–48, quality factor, Q × f r～21 000–23 500 GHz (at f r～5.5 GHz) and temperature coefficient of resonant frequency, TC f,～+115 ppm/K. |
| |
| Keywords: | |
|
|
