Microwave Dielectric Properties of BaTi5O11 Ceramics Prepared by Reaction‐Sintering Process with the Addition of CuO

BaTi 5 O 11 microwave dielectric ceramics prepared by reaction‐sintering process were investigated. BaCO 3 was mixed with TiO 2 and CuO, sintered to form BaTi 5 O 11 ceramics without any calcination stage involved. With 1 wt% CuO addition, monoclinic BaTi 5 O 11 ceramics were produced successfully after 3–9 h sintering at 1050°–1150°C. After sintering at 1100°C for 6 h, the BaTi 5 O 11 ceramics with the density of 4.49 g/cm 3 (98.2% of the theoretical value) and good microwave dielectric properties of ɛ r =41.2, Q × f =47 430 and τ f =36 ppm/°C have been obtained. The results show that the reaction‐sintering process is a simple and effective method to produce BaTi 5 O 11 ceramics for the applications of microwave dielectric resonators.