Pinning Effects on the Dielectric and Ferroelectric Properties of Mn-Doped Ba(Zr<sub>0.06</sub>Ti<sub>0.94</sub>)O<sub>3</sub> Ceramics

Lead-free ceramics with the composition of Mn-doped Ba(Zr 0.06 Ti 0.94 )O 3 – x mol%MnO 2 (BZT6- x Mn, x =0, 1 and 2) have been synthesized by a mixed oxide process. Structure and micrograph characterization were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM), which revealed that all samples have the orthorhombic phase with dense and the uniform microstructure. The grain size of Mn-doped BZT6 ceramics decreased with increasing MnO 2 doping. The effect of MnO 2 doping on the dielectric and ferroelectric properties was also investigated. The maximum dielectric permittivity decreased dramatically with increasing MnO 2 doping in the BZT6 ceramics. A peculiar double-hysteresis-like loop was observed. Mn ions as acceptor doping occupy the B site of ABO 3 in the form of Mn 2 + and Mn 3+ , which brought an increase in the oxygen vacancies concentration. The defect dipole model was explained the pinning mechanism.