Effects of Ba2+Doping on Microstructure and Properties of Plmnt Electro-Optic Ceramics Fabricated by Hot-Pressed Sintering Process

A series of highly transparent electro-optic (EO) ceramics Pb 0.975-x Ba x La 0.025 (Mg 1/4 Nb 1/2 Ti 1/4 ) 0.99375 O 3 with the Ba 2+ content of 0, 0.005, 0.01, 0.02, 0.04 were fabricated through the vacuum/oxygen hot-press sintering process. The effects of the barium substitution on the material phase transition, transmittance, dielectric, ferroelectric and electro-optic properties have been investigated and analysed. With the Ba 2+ content increasing, the shape of the ferroelectric hysteresis loop changed from rectangular to slim, the values of remnant polarization (P r ) and coercive electric field (E c ) decreased obviously. The maximum reduction of P r can reach up to ∼89.8%. All the samples present the high transparency of ~68% in the near infrared wavelength. The quadratic EO coefficients declines slightly while the Ba 2+ content increasing. When the x is 0.01, the sample shows a relatively larger quadratic EO coefficient of ~30.42×10 -16 (m/V) 2 and a lower P r value of ~2.08 μC/cm 2 , which promise the material a hopeful application in EO modulator.