Sintering behavior, structures and microwave dielectric properties of a rutile solid solution system: (AxNb2x)Ti1-3xO2 (A=Cu, Ni)

The sintering behavior, structures and microwave dielectric properties in a rutile solid solution system-(A(x)Nb(2x))Ti1-3xO2 (A=Cu, Ni)-were investigated and the samples were prepared by conventional solid state reaction method. Single phase of tetragonal rutile structure has been obtained through the entire range of compositions (0.02 a parts per thousand currency signaEuro parts per thousand x a parts per thousand currency signaEuro parts per thousand 0.20). The sintering temperature was lowered to 900A degrees C by (Cu (x) Nb-/3(2x/3))(4+) substituting for Ti4+ in the solid solution. Comparing with that of rutile TiO2 (465 ppm/A degrees C), the temperature coefficient of resonant frequency (TCF) of the rutile solid solution is much lower (about 250 ppm/A degrees C), and the dielectric constant and the quality factor (Qf value) of the solid solution are about 70 similar to 80 and 7,000G Hz. The substitution of (Cu (x) Nb-/3(2x/3))(4+)or (Ni (x) Nb-/3(2x/3))(4+) for Ti4+ in the solid solution improved the microwave dielectric properties of the rutile TiO2 ceramics.