Structure-property relations in xCaTiO3-(1-x)SrMg1/3Nb2/3O3 based microwave dielectrics

Solid solutions of the system (x)CaTiO3-(1-x)Sr(Mg1/3Nb2/3)O3 (CTSMN) were prepared by the mixed oxide route. All compositions were found to be single phase by X-ray diffraction; pellets had densities > 95% of the theoretical X-ray density. Scanning electron microscopy coupled with energy dispers...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of the European Ceramic Society 2003, Vol.23 (14), p.2435-2441
Hauptverfasser: BAGSHAW, H, IDDLES, D, QUIMBY, R, REANEY, I. M
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Solid solutions of the system (x)CaTiO3-(1-x)Sr(Mg1/3Nb2/3)O3 (CTSMN) were prepared by the mixed oxide route. All compositions were found to be single phase by X-ray diffraction; pellets had densities > 95% of the theoretical X-ray density. Scanning electron microscopy coupled with energy dispersive X-ray analysis revealed a homogeneous distribution of cations within instrument sensitivity in all samples except for pure SMN which showed evidence of some unreacted MgO. SMN is reported as a 1:2 ordered trigonal/hexagonal complex perovskite structure in the X-ray data files but electron diffraction revealed superlattice reflections characteristic of both in-phase and anti-phase rotations of octahedra arising from further structural phase transitions on cooling. These reflections were retained throughout the solid solution range but #+1/3{hkl} ordered superlattice reflections were absent in samples where x > 0.1. In general, the microwave quality factor (Qu*fo) decreased as x increased and the temperature coefficient of resonant frequency (TCf) was approximately linearly proportional to the permittivity; at x~0.20: TCf~0, *er ~45 and Qu*fo ~9000.
ISSN:0955-2219
1873-619X
DOI:10.1016/s0955-2219(03)00132-8