Search Results

1 - 2 of 2 items

  • Author: H. Bruncková x
Clear All Modify Search

Abstract

Neodymium niobate NdNbO4 (NNO) and tantalate NdTaO4 (NTO) thin films (~100 nm) were prepared by sol-gel/spin-coating process on Pb(Zr0.52Ti0.48)O3/Al2O3 substrates with annealing at 1000°C. The precursors of films were synthesized using Nb or Ta tartrate complexes. The XRD results of NNO and NTO films confirmed tetragonal T-NdNbO4 and T-NdTaO4 phases, respectively, with traces of monoclinic MNdNbO4 and M´-NdTaO4. The surface morphology and topography were investigated by SEM and AFM analysis. NTO was smoother with roughness 5.24 nm in comparison with NNO (6.95 nm). In the microstructure of NNO, small spherical (~ 20-50 nm) T-NdNbO4 and larger needle-like particles (~100 nm) of M-NdNbO4 phase were observed. The compact clusters composed of fine spherical T-NdTaO4 particles (~ 50 nm) and cuboidal M´-NdTaO4 particles (~ 100 nm) were found in NTO. The results of this work can contribute to formation of different polymorphs of films for the application in environmental electrolytic thin film devices.

Abstract

Samarium niobate SmNbO4 (SNO) and tantalate SmTaO4 (STO) thin films (~100 nm) were prepared by sol-gel/spin-coating process on alumina substrates with PZT interlayer and annealing at 1000°C. The precursors of films were synthesized using Nb or Ta tartrate complexes. The improvement of the crystallinity of monoclinic M′-SmTaO4 phase via heating was observed through the coexistence of small amounts of tetragonal T-SmTa7O19 phase in STO precursor at 1000°C. The XRD results of SNO and STO films confirmed monoclinic M-SmNbO4 and M′-SmTaO4 phases, respectively, with traces of orthorhombic O-SmNbO4 (in SNO). In STO film, the single monoclinic M′-SmTaO4 phase was revealed. The surface morphology and topography of thin films were investigated by SEM and AFM analysis. STO film was smoother with roughness 3.2 nm in comparison with SNO (6.3 nm). In the microstructure of SNO film, small spherical (~50 nm) and larger cuboidal particles (~100 nm) of the SmNbO4 phase were observed. In STO, compact clusters composed of fine spherical SmTaO4 particles (~20-50 nm) were found. Effect of samarium can contribute to the formation different polymorphs of these films for the application to environmental electrolytic thin film devices.