Improvement of microwave dielectric properties of Ba2Ti9O20 ceramics using [Zn1/3Nb2/3]4+substitution for Ti4+

Ba-2[Zn1/3Nb2/3](x)Ti9-xO20(x = 0-0.5) ceramics with high-quality factors were successfully prepared via traditional solid-state method. In this work, the microstructure and microwave dielectric properties of the samples were studied. The X-ray diffraction patterns indicated that two different phases BaTi(4)O(9)and Ba(2)Ti(9)O(20)existed atx = 0, while the phase of Ba(2)Ti(9)O(20)was found gradually dominating in specimens with the doping of [Zn1/3Nb2/3](4+). At the level ofx = 0.5, a fraction of the monoclinic phases of Ba(2)Ti(9)O(20)were transformed into the triclinic phase. Furthermore, the SEM and relative density were used to confirm the homogeneous microstructure of the Ba-2[Zn1/3Nb2/3](x)Ti(9-x)O(20)ceramics. The doping of [Zn1/3Nb2/3](4+)can effectively improve the microwave properties of Ba(2)Ti(9)O(20)ceramics, which are shown as the increase of dielectric constant, quality factor, and the stability of temperature coefficient. Particularly, the excellent microwave dielectric properties were achieved for the Ba-2[Zn1/3Nb2/3](0.3)Ti(8.7)O(20)ceramics sintered at 1300 degrees C, with epsilon(r) similar to 39.3, a highQ x f similar to 43,879 at 6 GHz, and a tau(f) similar to + 7 ppm/degrees C.