Thermally stable BaTiO_3-Bi(Zn_(0.75)W_(0.25))O_3 solid solution with high relative permittivity and low dielectric loss

摘要

(1-x)BaTiO_3-Bi(Zn_(0.75)W_(0.25))O_3 [BT-BZW, 0 ≤ x ≤ 0.2] solid solutions were fabricated via a conventional solid-state reaction method. The relationships among compositions, crystal structures, and dielectric properties were investigated. X-ray diffraction patterns showed that a phase transformation from tetragonal to pseudocubic was observed at 0.03 ≤ x ≤ 0.1. Raman spectra analysis also illustrated that the long-range ferroelectric order is disrupted from these compositions. Dielectric data showed that as the BZW addition was small (0.01 ≤ x ≤ 0.04), the magnitude of permittivity maxima decreased, and the Curie temperature was almost irrespective of BZW content (x). While the dielectric temperature stability and relative permittivity of BT below the Curie temperature were effectively improved. In particular, the ceramic with x = 0.04 possesses the dielectric properties with high permittivity (～ 3,000), low dielectric loss (＜3 %) and dielectric temperature stability (±15 %) in the temperature range of 25-125 ℃, indicating this ceramic satisfies the requirement of EIA X7R specifications. Especially for x = 0.2, the variations of Δε/ε_(100) ℃ is around ±15 % over a wide temperature range from 100 to 400 ℃, suggesting potential usage at elevated temperatures.