Structural and electrical properties of strontium barium niobate thin films crystallized by conventional furnace and rapid-thermal annealing process

Abstract

Strontium barium niobate (SBN) thin films were crystallized by conventional electric furnace annealing and by rapid-thermal annealing (RTA) at different temperatures. The average grain size of films was 70 nm and thickness around 500 nm. Using x-ray diffraction, we identified the presence of polycrystalline SBN phase for films annealed from 500 to 700°C in both cases. Phases such as SrNb 2 O 6 and BaNb 2 O 6 were predominantly crystallized in films annealed at 500°C, disappearing at higher temperatures. Dielectric and ferroelectric parameters obtained from films crystallized by conventional furnace and RTA presented essentially the same values.

Investigation of nonlinear dielectric properties in Sr0.75Ba0.25Nb2O6 relaxor ferroelectric thin films

“…So, the obtained results for the studied SBN75/25 thin film indicate that if there exists some component of the parasitic capacitance, its contribution to the obtained dielectric response is weak, because of the weak dielectric dispersion obtained for temperatures above T m in the present work. Therefore, it can be pointed out that the observed characteristics for the SNB75/25 thin films near the transition temperature, such as the decrease of Ј and its corresponding maximum temperature ͑T m ͒ and the increase of the phase transition diffuseness, when compared to the ceramics and single crystals results, can be associated with the small grain size distribution of the film ͑ϳ50 nm͒, 23 as well as to an additional little component of a mechanic tensile at the film-substrate interface.…”

Mesoscopic structure evidenced by AC dielectric nonlinearities in Sr0.75Ba0.25Nb2O6relaxor ferroelectric thin films

“…Sr 0.75 Ba 0.25 Nb 2 O 6 (hereafter labelled as SBN75/25) thin films, with 500 ± 20 nm thickness, determined by scanning electron microscopy, were prepared by a chemical route and deposited on Pt/Ti/SiO 2 /Si substrates as previously reported [14]. Xray diffraction patterns (not shown here) and energy dispersive x-ray spectroscopy analysis revealed a single polycrystalline tetragonal SBN phase and the expected nominal composition.…”

“…Xray diffraction patterns (not shown here) and energy dispersive x-ray spectroscopy analysis revealed a single polycrystalline tetragonal SBN phase and the expected nominal composition. For dielectric investigations, gold electrodes (0.5 mm in diameter) were sputtered on thin film surfaces forming a metal-film-metal configuration, as previously reported [14]. Computer assisted dielectric measurements were performed as a function of temperature, frequency (1 kHz-1 MHZ) and measurement AC electric field amplitude (E m ), up to 20 kV cm −1 , using an HP4194A impedance gain/phase analyser.…”

“…SBN thin films have been synthesized by various methods, such as radiofrequency sputtering [11], sol-gel [12], and laser ablation [13] techniques, where only the structural and/or ferroelectric properties have been taken into account. Recently, a modified chemical route was successfully employed to obtain high quality SBN thin films [14], which presented structural and ferroelectric characteristics compatible with those obtained by other traditional routes [12][13][14][15]. Despite their very attractive physical properties, and to the best of our knowledge, there have been few experimental works concerning the dielectric nonlinearities in SBN thin films.…”

Synthesis and characterisation of four new heterometal alkoxides: potential precursors for the MOCVD of ferroelectric oxides

“…Multicomponent metal oxides containing strontium and tantalum, and strontium and niobium, have a variety of important technological applications. For instance, the layered structure perovskites strontium bismuth tantalate, SrBi 2 Ta 2 O 9 (SBT), strontium bismuth niobate, SrBi 2 Nb 2 O 9 (SBN), and strontium bismuth tantalate niobate, SrBi 2 (Ta x Nb 12x ) 2 O 9 (SBTN) are promising materials for non-volatile ferroelectric memory (FeRAM) applications, due to their low polarisation fatigue and low coercive switching threshold. 1 Strontium barium niobate, (Sr,Ba)Nb 2 O 6 is another useful material, 2 whose large pyroelectric coefficient, piezoelectric and electrooptic properties give it a variety of potential applications in integrated optical devices.…”