Phase evolution and dielectric properties of Ba(Ti_(1/6)Sn_(1/6)Zr_(1/6)Hf_(1/6)Nb_(1/6)Ga_(1/6))O_3 high-entropy perovskite ceramics

摘要

High-entropy ceramics (HECs), Ba(Ti_(1/6)Sn_(1/6)Zr_(1/6)Hf_(1/6)Nb_(1/6)Ga_(1/6))O_3, with perovskite structure were successfully synthesized through solid-state reaction method. HECs can be divided into three stages in the calcination process: from multiphase state to two-phase state and finally to single-phase perovskite structure. High entropy is the main driving force for the formation of perovskite HECs. The equilibrium phase of 1500 °C was transformed back to its multiphase state at low temperature, and vice versa on heating. The elements of the HECs are homogeneously distributed, and the relative density of the ceramic is 92.7%. The microstructures are fine, in which the average grain size is less than 1 urn. The dielectric constant eT and loss tangent tan 8 exhibit slightly frequency dispersion.