Influence of different heat treatment programs on properties of sol–gel synthesized (Na0·5K0·5)NbO3 (KNN) thin films

Abstract

Thin films of (Na 0•5 K 0•5)NbO 3 (KNN) were synthesized on Pt/Ti/SiO 2 /Si substrates with repeated spin-coating after fabrication of the precursor solution by a sol-gel process. The KNN precursor solution was prepared from K-and Na-acetate, Nb-pentaethoxide and 1,3-propanediol. Based on three characteristic temperatures derived from thermal analysis (TG-DTA) experiments, five heat treatment programs were developed. All programs lead to single phase perovskite KNN films with random crystal orientation, but only the programs that included a treatment after each single spin-coating step provided pore free surfaces with grains of about 100 nm size. The lowest leakage current at 150 kV cm −1 was obtained for the temperature program that included pyrolysis and calcination steps after each deposited layer.

Optical and Microwave Dielectric Properties of Phase Pure (K0.5Na0.5)NbO3 Thin Films Deposited by RF Magnetron Sputtering

“…These values are in good agreement with the pseudocubic unit cell parameters ( a = 4.0054 Å, b = 3.9551 Å, c = 4.0054 Å) reported by Ishizawa et al . Wiegand et al . reported the lattice parameter of a = 3.970 Å for KNN thin films prepared by the sol–gel process.…”

Investigation of microstructural and optical properties of (K,Ba)(Ni,Nb)O3−δ thin films fabricated by pulsed laser deposition

“…This indicated a structural transition from orthorhombic to cubic. However, from the XRD peaks of KBNNO film, the splitting of the doublet characteristics of the orthorhombic/tetragonal structure is not observed clearly, except the peaks at around 45°, which reveals a pseudo-cubic structure [13], as shown in the inset of Fig. 2.…”

Advanced Synthesis on Lead‐Free KxNa(1−x)NbO3 Piezoceramics for Medical Imaging Applications

“…The similar sol–gel synthesis with niobium ethoxide as precursor and 1,3 propanediol as solvent that bridging ligand to crosslink the ions and generate the network. The most performing sample treated at 500/600 °C, showed a remnant polarization, a coercive field of 214 kV cm −1 and electric field of 150 kV cm −1 . Yao et al use the same method but starting from different metallic precursors.…”