Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Crystal structure, Raman vibrational characteristics, and microwave dielectric properties of Mg2−xCoxTiO4 ceramics
Ist Teil von
Journal of materials science. Materials in electronics, 2024-02, Vol.35 (4), p.294, Article 294
Ort / Verlag
New York: Springer US
Erscheinungsjahr
2024
Link zum Volltext
Quelle
SpringerLink
Beschreibungen/Notizen
A series of Mg
2−
x
Co
x
TiO
4
(
x
= 0.0, 0.5, 1.0, 1.5, 2.0) ceramics were synthesized by a conventional solid-state reaction route. The crystal structure, Raman vibrational characteristics, sintering behavior, microstructure, and microwave dielectric properties were systematically investigated. X-ray diffraction patterns and Raman spectroscopy indicated that the Mg
2−
x
Co
x
TiO
4
ceramics all exhibited a single-phase structure with cubic spinel (space group: Fd
3
¯
m). The lattice parameters gradually increased with the continuous doping of Co
2+
ions according to the Rietveld refinement results. Structure–property relationships were established based on Clausius–Mossotti equations, Raman spectroscopy, and bond valence theory. The
ε
r
values of Mg
2−
x
Co
x
TiO
4
ceramics were significantly affected by the ionic polarizability and the [Mg
1
/Co
1
O
4
] stretching vibration. The variation tendency of the
Q
×
f
values was closely related to the densification, and packing fraction. Moreover, the “rattling” effect at the A-site, the bond valence of the B-site, and the oxygen bond valence played an important role in controlling the
τ
f
values of Mg
2−
x
Co
x
TiO
4
single-phase ceramics. An excellent microwave dielectric property of
ε
r
= 15.88,
Q
×
f
= 38,157 GHz, and
τ
f
= − 32.21 ppm/°C can be obtained for Mg
2−
x
Co
x
TiO
4
ceramics with
x
= 1.0 sintered at 1350 °C for 4 h.