Effects of niobium content on electrical and mechanical properties of (Na_(0.85)K_(0.15))_(0.5)Bi_(0.5)Ti_((1-x))Nb_xO_3 thin films

摘要

(Na_(0.85)K_(0.15))_(0.5)Bi_(0.5Ti_((1-x))Nb_xO_3→(NKBT-N100x) thin films were deposited on Pt/Ti/SiO_2/Si(100) substrates by metal-organic decomposition method and annealed in oxygen atmosphere at 750 ℃. The effects of niobium concentration on the microstructures, ferroelectric, piezoelectric, leakage current and mechanical properties of the NKBT-N100x (x ＝ 0, 0.01, 0.03, 0.05) thin films have been investigated in detail. The NKBT-3N thin film has the largest remnant polarization (7 μC/cm~2) and statistically averaged d_(33eff) (140 pm/V), the smallest leakage current, elasticity modulus (102.0 Gpa), hardness (5.1 Gpa) and residual stress (297.0 Mpa). The evaluation of residual stresses of these thin films will offer useful guidelines of safe working condition for their potential application in microelectromechanical system.