Structure and ferroelectric properties of high TcBi(Me)O3-PbTiO3 single crystal thin films

• Main Authors: Wasa, K., Hanzawa, H., Yoshida, S., Tanaka, S., Adachi, H., Matsunaga, T.
• Format: Conference Proceeding
• Language: eng ; jpn
• Subjects: beyond PZT; BS-xPT thin films; Crystals; Epitaxial growth; high Curie temperature; Lattices; relaxed single crystal thin films; sputtered hetero-epitaxial thin films; Substrates; Temperature; Temperature measurement
• ISSN: 1099-4734; 2375-0448
• DOI: 10.1109/ISAF.2015.7172663

Pb(Zr,Ti)O 3 (PZT) piezoelectric ceramics with higher Curie temperature T c are necessary for a fabrication of better micro actuators, sensors, memories and/or piezoelectric micro electromechanical systems(MEMS). New piezoelectric materials with higher T c beyond PZT are extensively studied. Among the new piezoelectric materials, Bi(Me)O 3 -xPbTiO 3 ceramics(Me: Yb, In, Sc) are fascinated for the higher T c materials. In this paper thin films of single crystal (1-x)BiScO 3 -xPbTiO 3 (BS-xPT) were deposited by an rf-magnetron sputtering for a better understanding of ferroelectric performance of the BS-xPT. We have made a laminated composite structure comprising relaxed hetero-epitaxial single crystal thin films of high T c BS-xPT (0.5≤x≤0.8) and SrRuO 3 (SRO)/Pt/MgO hetero-structural substrates. It was confirmed their ferroelectric performances of the BS-xPT thin films were comparable to the PZT based thin films: a thin film transverse piezoelectricity e 31,f was -6.7C/m 2 at x=0.8 with 2P r =~60μC/cm 2 , 2E c =~250 kV/cm, and ε/ε o =~150. The BS-0.8PT thin films exhibit extraordinary high T c with T c =750°C. The enhanced T c is caused by the presence of the high temperature stable interface in the laminated composite structure. The present BS-xPT thin films have a high potential for a fabrication of high temperature stable piezoelectric MEMS beyond PZT.