Phase, microstructure and microwave dielectric properties of Mg_0:95Ni_0:05Ti_0:98Zr_0:02O₃ ceramics

Abstract

Mg 0.95 Ni 0.05 Ti 0.98 Zr 0.02 O 3 ceramics was prepared via conventional solid-state mixed-oxide route. The phase, microstructure and microwave dielectric properties of the sintered samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and a vector network analyzer. The microstructure comprised of circular and elongated plate-like grains. The semi quantitative analysis (EDS) of the circular and elongated grains revealed the existence of Mg 0.95 Ni 0.05 T 2 O 5 as a secondary phase along with the parent Mg 0.95 Ni 0.05 Ti 0.98 Zr 0.02 O 3 phase, which was consistent with the XRD findings. In the present study, ε r ∼17.1, Q u f o ∼195855 ± 2550 GHz and τ f ∼ −46 ppm/K was achieved for the synthesized Mg 0.95 Ni 0.05 Ti 0.98 Zr 0.02 O 3 ceramics sintered at 1325°C for 4 h.

Phase and Microstructure Evaluation and Microwave Dielectric Properties of Mg1−x Ni x SiO3 Ceramics

“…2) that shifted towards larger 2h values. In the present study e r $ 7.67 was obtained for the composition with x = 0 (MgSiO 3 ) sintered at 1450°C for 9 h, which is greater than that obtained in a previous study for MgSiO 3 (e r $ 6.50) 9 .…”

“…A low dielectric constant (e r < 10) to minimize the cross-coupling with the conductors and to reduce the time for electronic signal transmission, a high unloaded quality factor multiplying the resonant frequency (Q u f o ) to lower the power dissipation and increase the selectivity of signal frequency and a near zero temperature coefficient of resonant frequency (s f ) for the frequency stability under the working environment temperature is required. [1][2][3] Silicates possess low e r due to having about 55% covalent bonding in silica tetrahedron (SiO 4 ).Therefore, they are considered to be one of the good candidates for millimeter-wave dielectric ceramics. [4][5][6][7][8] Forsterite (Mg 2 SiO 4 ) has been extensively investigated for millimeter wave applications due to low dielectric constant (about e r : 7.0) and high Q u f o value.…”