Structural, dielectric and piezoelectric properties of (Bi_(0.5)Na_(0.5))TiO_3-(Bi_(0.5)K_(0.5))TiO_3-Bi(Zn_(0.5)Ti_(0.5))O_3 thin films prepared by sol-gel method

摘要

Lead free (1-x)(0.8Bi_(0.5)Na_(0.5)Ti_(0.5)O_3-0.2Bi_(0.5)K_(0.5)TiO_3)-xBiZn_(0.5)Ti_(0.5)O_3 (x=0-0.06) (BNT-BKT-BZT) thin films were deposited on Pt (111)/Ti/SiO_2/Si( 100) substrates by a sol-gel processing technique. The effects of BZT content on the structural, dielectric, ferroelectric and piezoelectric properties of the BNT-BKT-BZT thin films were investigated systematically. The BNT-BKT-BZT thin films undergo a transition from ferroelectric to relaxor phase with increasing temperature. The phase transition temperature decreases with the increase of BZT content. The BNT-BKT-BZT thin film with x=0.04 exhibits the best ferroelectric properties (P_(max)=40 μC/cm~2 and P_r=10 μC/cm~2), largest dielectric constant (ε =560) and piezoelectric constant (d_(33) = 40 pm/V). This finding demonstrates that the BNT-BKT-BZT thin film has an excellent potential for demanding high piezoelectric properties in lead free films.