Effect of Ho Doping on Structure and Ferroelectric Property of Bi4-xHoxTi3O12 Ceramics

Ho-doped bismuth titanate (Bi4-xHoxTi3O12) ceramics were prepared by hot-press sintering. The effects of Ho doping on the crystalline phase, density, microstructure and ferroelectric property of the ceramics were investigated. At first, Bi4-xHoxTi3O12(x=0-0.8) powders in the main phase of Bi4Ti3O12 were synthesized from Bi2O3, TiO2 and Ho2O3 micro-powders by solid-state reaction at 900 The as-synthesized powders were then sintered by hot-press at 850 nd 30 MPa to prepare Bi4-xHoxTi3O12 ceramics. With the appropriate Ho doping content of x=0-0.4, single-phased and dense (relative density >99%) Bi4-xHoxTi3O12 ceramics were obtained. The remanent polarization (Pr) of the ceramics increased with Ho doping increasing but decreased at x>0.4, mainly due to the oxygen vacancy concentration and different doping sites. The Bi4-xHoxTi3O12 ceramics have the highest value of 2Pr=13.92 μC/cm2 at x=0.4, which is higher that that of the undoped Bi4Ti3O12 ceramics. The result indicates that appropriate Ho doping can improve the ferroelectric property of Bi4Ti3O12 ceramics.