Oana Andreea Condurache

Jožef Stefan Institute | IJS · Department of Electronic Ceramics

Ferroelectric domain dynamics is at the heart of any ferroelectric-based application. In situ transmission electron microscopy (TEM) offers an exciting opportunity to directly image ferroelectric switching and domain dynamics, revealing phenomena that might be concealed in macroscopic measurements. Here, we investigate the voltage-driven response o...

The atomic-level response of zigzag ferroelectric domain walls (DWs) was investigated with in situ bias scanning transmission electron microscopy (STEM) in a subcoercive-field regime. Atomic-level movement of a single DW was observed. Unexpectedly, the change in the position of the DW, determined from the atomic displacement, did not follow the pos...

Pure perovskite 1%Eu – BaZryTi1-0.0025-yO3 ceramics with compositions y=0, 0.05, 0.15, and 0.30 prepared by solid-state reaction were investigated by impedance spectroscopy and high field measurements (P(E), dc-tunability). The ceramic samples present a nonlinear dielectric character and the dc-tunability reaches a maximum for y = 0.15 (nr = 85%) d...

Flexible composites containing BaTiO3 nanoparticles into Gelatin bio-polymer matrix were designed and investigated. Following the idea that the electric field concentration in corners/edges at the interfaces between dissimilar materials give rise to enhanced effective permittivity in composites, cuboid-like BaTiO3 nanoparticles have been employed a...

The integration of functional ceramics with metals remains challenging due to the thermally activated processes and the incompatibilities that arise during the high-temperature ceramic sintering process. In order to overcome this, low-temperature processing methods can be employed. In this work, dense 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 thick films were...

Bismuth ferrite (BiFeO3) is an attractive multiferroic material that shows strong ferroelectric and antiferromagnetic properties. Nevertheless, producing high-quality oriented BiFeO3 on technology-important platinized silicon substrates by low-cost solution deposition methods is still challenging. In this work, polycrystalline Mn and Ti co-doped Bi...

In this work, we demonstrate an approach for improving ferroelectric properties of La:HfO2 thin films by shifting the grain growth regime toward heterogeneous nucleation. A dilute 0.083 M instead of a 0.25 M solution together with an annealing step after every spin-coating cycle film gives rise to a significant improvement of ferroelectric properti...

The preparation and properties of BaTiO3 nanostructured ceramics with porosity level in the range of percolation limit (33% and 37% porosity) produced by partial sintering of cubic nanoparticles are presented. Hydrothermally synthesized cuboid-like particles were produced by using Field-Assisted Sintering Technique facility in which temperature and...

The dynamics of domain walls (DWs) during polarization switching has a great influence on the electromechanical response of ferroelectrics. To understand the influence of DWs on the functional performance of the material, their local structure and properties must be revealed. There are many investigations of the DWs in ferroelectric thin films, whi...

Bi0.88Gd0.12FeO3 multiferroics are of interest for next-generation electronics and are shown with a remnant magnetization 0.2 emu·g⁻¹, coercive field 8 kOe, Curie temperature 370 °C and magnetization of 0.7 emu·g⁻¹ at magnetic fields 30 kOe. Scanning probe microscopy confirmed the intrinsic multiferroicity in the perovskite phase with coexistence o...

We report on a heterogeneity study, down to the atomic scale, on a representative multiple-element-modified ceramic based on potassium sodium niobate (KNN): 0.95(Na 0.49 K 0.49 Li 0.02)(Nb 0.8 Ta 0.2)O 3-0.05CaZrO 3 with 2 wt % MnO 2. We show that different routes for incorporating the MnO 2 (either before or after the calcination step) affect the...

Electronic devices, designed to be long lasting, are commonly made with rigid, non-degradable materials. This, together with the presence of rare and toxic elements, creates significant issues for their waste management. The production of electronic devices, made with biodegradable materials that are sourced from waste streams of the agricultural s...

This poster summarises our work: G. Canu et al., Structure-property correlations and origin of relaxor behaviour in BaCexTi1-xO3, Acta Materialia 152, 258–268 (2018). The incorporation of homovalent M4+ ions at the Ti site of BaTiO3 with formation of the BaMxTi1-xO3 solid solutions (M = Sn, Zr, Hf, Ce) determines significant modifications of the p...

The ability to tune and enhance the properties of luminescent materials is essential for enlarging their application potential. Recently, the modulation of the photoluminescence emission of lanthanide-doped ferroelectric perovskites by applying an electric field has been reported. Herein, we show that the ferroelectric order and, more generally the...

In the present work, composite ceramics of ferroelectric BaTiO3 with magnetic αFe2O3 were prepared by mixing powders in different ratio. The M(H) loops at room temperature show a “wasp-waisted” character, with multiple components, determined as result of the formation of magnetic phases with contrasting coercivities (hard BaFe12O19 and soft Ba12Ti2...