Microwave dielectric properties of temperature‐stable zircon‐type (Bi, Ce)VO 4 solid solution ceramics

In the (Bi 1 − x Ce x )VO 4 (0 ≤ x ≤ 1) system, we found that the (Bi 1 − x Ce x )VO 4 (0 ≤ x ≤ 0.1) belongs to the monoclinic scheelite phase and the (Bi 1 − x Ce x )VO 4 (0.7 ≤ x ≤ 1) belongs to the tetragonal zircon phase, while the (Bi 1 − x Ce x )VO 4 (0.1 < x < 0.7) belongs to the mixed phases of both monoclinic scheelite and tetragonal zircon structure. Interestingly, two components with near‐zero temperature coefficient of resonant frequency (TCF) appeared in this system. In our previous work, a near‐zero TCF of ~+15 ppm/°C was obtained in a (Bi 0.75 Ce 0.25 )VO 4 ceramic with a permittivity (ε r ) of ~47.9 and a Qf (Q = quality factor = 1/dielectric loss; f = resonant frequency) value of ~18 000 GHz (at 7.6 GHz). Furthermore, in the present work, another temperature‐stable microwave dielectric ceramic was obtained in (Bi 0.05 Ce 0.95 )VO 4 composition sintered at 950°C and exhibits good microwave dielectric properties with a ε r of ~11.9, a Qf of ~22 360 GHz (at 10.6 GHz), and a near‐zero TCF of ~+6.6 ppm/°C. The results indicate that this system might be an interesting candidate for microwave device applications.