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(Ti, Zn)-co-doped Bi0.97Nd0.03FeO3(BNFTZ) thin films with different thicknesses were prepared directly on indium tin oxide/glass substrates deriving from the precursor solutions with different solution concentrations. The X-ray diffraction, scanning electron microscopy and insulating/ferroelectric/dielectric measurements were utilised to characterise the BNFTZ thin films. Both BNFTZ thin films with the thicknesses of 160 and 320 nm are crystallised into phase-pure perovskite structure without second phase. Compared to the film of 160 nm, a lower leakage current can be obtained in BNFTZ film of 320 nm due to due to its denser microstructure with smaller grain size. The film with 320 nm thickness possesses a high energy-storage efficiency of 87%, which can be ascribed to the slimP–Eloop. At 100 kHz, the film of 320 nm owns lower dielectric constant (~91) and dissipation factor (~0.10). The possible contributions are discussed to explain the difference in the related performances for BNFTZ thin films with different thicknesses. [ABSTRACT FROM AUTHOR]

Dislocations form in epitaxial thin films above a critical thickness, when the stress due to the film-substrate mismatch becomes excessive. This phenomenon has been extensively investigated in non-piezoelectric thin films. In piezoelectric films, the mismatch strain field and the electric field are coupled, and the critical thickness depends on an extra physical variable: the electric field. In this paper, the critical thickness for dislocation formation in a piezoelectric film is derived. The dependence of the critical thickness on the piezoelectric properties of the Al x Ga 1- x N/GaN system is then discussed. [ABSTRACT FROM AUTHOR]