Effect of d-transition element oxides on polycrystalline rutile properties

To define the contribution of Nb2O5, MoO3, V2O5 small quantities into the effect of rutile permittivity increase at high and syperhigh frequencies, the interrelation of rutile dielectric, physicochemical properties at the introduction of preset quantities of oxides of α-transition elements was investigated. Density and porosity of saumples were determined by the method of hydrostatic weighing. It is ascertained that oxide additions affect the tendency to sintering rutile ceramics samples. Ceramics density decreases, open porosity enhances, colour and dielectric properties change as the quantity of introduced additions increases. The maximum value epsilon at SHF equals 120 and is noted for rutile containing O.83 mass % Nb2O5. The introduction of 0.5 mass % MoO3 produces a weaker effect on rutile epsilon:epsilon sub(max)=100. The introduction of 0.1-1.0 mass % V2O5 does not practically change rutile epsilon. It is shown that the anomalous increase of epsilon value of rutile ceramics after the introduction of Nb2O5 and MoO3 small additions is caused by the substitution of Nb5+ and Mo6+ cations for Ti4+ cations. Temperature coefficient of permittivity is measured in 20-600 deg C range. Temperature dependences of permittivity of rutile with different contents of oxides (20-600 deg C) are studied