Annealing Temperature-Dependent Structural, Optical, and Electrical Properties of [(Ba_1−zCa_z)(Zr_0.1Ti_0.9)O₃], (z = 0.155), Films

Abstract

Thin films were deposited on quartz and p-Si (100) substrates by radio frequency sputtering of ceramic barium calcium zirconate titanate [(Ba1-zCaz)(Zr0.1Ti0.9)O3],(z = 0.155), target. The as-deposited films were annealed for one hour at different temperatures, between 500 and 800°C. The occurrence of film crystallization was observed on annealing at and above 600°C. However, films peeled out on annealing at 800°C. The structure, optical transmittance, dielectric constant, and leakage current of the prepared films (hereafter referred to as BCZT0.9 films), annealed at different temperatures, were measured. The optical bandgap of the BCZT0.9 films was found to reduce from 4.24 to 3.87 eV with the increase in annealing temperature. On crystallization, the leakage current density of the prepared films decreased by an order of three, from ~10-6 for amorphous to ~10-9 A/cm2 for crystalline films. The current-voltage variations of the prepared films exhibit different conductions for different annealing treatments. The dielectric constant was obtained maximum, 148 (at 1 MHz), and leakage current density minimum, 3.6 × 10-9 A/cm2 (at 3.0 × 102 kV/cm electric field), for the films annealed at 750°C. Electrical properties were observed to improve for the films annealed at 750°C than other annealed films.

On the Evolution of Stress and Microstructure in Radio Frequency-Sputtered Lead-Free (Ba,Ca)(Zr,Ti)O3 Thin Films

“…There are very few reports overall on the in-plane stress of BCZT on Si in the literature. One exemption, by Biswas et al [37], found smaller values using XRD, yet also experienced film peeling for films annealed at 800 • C, comparable to this work. This was found for BCZT films deposited directly onto oxidized Si substrates without a bottom electrode, and here these were also found to have slightly lower stress than the ones grown on platinized Si (see Figure 5).…”

Impedance Spectroscopy and AC Conductivity Analysis of (Ba1−kCak)(Zr0.1Ti0.9)O3, (0.140 ≤ k ≤ 0.160), Ceramics

“…can be significantly changed by varying the annealing temperature of the prepared films of (Ba 1−k Ca k )(Zr 1−z Ti z )O 3, (k = 0.155, z = 0.9) ceramic. 19 Also, improved dielectric constant and low leakage current density were observed for higher annealing temperatures. 19 Comparatively leadfree perovskite ferroelectric (Ba 1−k Ca k )(Zr 1−z Ti z )O 3 may be a promising material for optoelectronic and other applications like optical coatings, band-gap engineering, memory devices, etc.…”