Colossal permittivity and low dielectric loss in niobium and europium co-doped TiO2 ceramics by adding B2O3

Abstract The application of numerous colossal permittivity (CP, > 10 3 ) materials was limited on account of relatively higher dielectric loss (>0.05). In this work, the x wt% B 2 O 3 ( x  = 0, 0.5, 1, 2, 4) adding Ti 0.99 (Eu 0.5 Nb 0.5 ) 0.01 O 2 (TENO- x wt% B 2 O 3 ) ceramics were prepared by a traditional solid state method. SEM analysis indicated that the average grain sizes obviously decreased by adding B 2 O 3 and the low dielectric loss corresponding with the colossal permittivity were obtained in all samples. Especially, the higher permittivity of 4.1 × 10 4 and lower dielectric loss of 0.012 were achieved while x  = 2 at 1 kHz and room temperature respectively, accompanying with good temperature stability ranging from −55 °C to 200 °C. Moreover, the formation mechanism of excellent dielectric properties was studied on the basis of analysis of the SEM, complex impedance and electric modulus. The results showed that the addition of B 2 O 3 refined the grains and strengthened the interface effect. Furthermore, the B 2 O 3 existing in the grain boundary formed barrier layer which hindered the long range motion of electrons.