Novel synthetic routes to prepare functional oxides at lower temperatures are an increasingly important area of research. Many of these synthetic routes, however, use water as the solvent and rely on dissolution of the precursors, precluding their use with, for example, titanates. Here we present a low cost solvent system as a means to rapidly create phase-pure ferroelectric barium titanate using a choline chloride-malonic acid deep eutectic solvent. This solvent is compatible with alkoxide precursors and allows for the rapid synthesis of nanoscale barium titanate powders at 950 °C. The phase and morphology were determined, along with investigation of the synthetic pathway, with the reaction proceeding via BaCl2 and TiO2 intermediates. The powders were also used to create sintered ceramics, which exhibit a permittivity maximum corresponding to a tetragonal-cubic transition at 112 °C, as opposed to the more conventional temperature of ~ 120 °C. The lower-thanexpected value for the ferro-to para-electric phase transition is likely due to undetectable levels of contaminants.

A finite element modelling - experimental approach as a new resource efficient design strategy to improve the temperature stability of BaTiO3 (BT)-based ceramic materials for MLCCs. Illustrated using rare earth-free NaNbO3-doped BT and found to decrease the magnitude of the TCC.

In this article, we report on the liquid-crystalline properties of two series of halogen-terminated cyanobiphenylbased materials. Unlike other rod-shaped, halogen-terminated materials reported, these materials do not exhibit the smectic A phase and instead only exhibit nematic liquid-crystal mesomorphism. Comparisons between these materials and analogous unsubstituted materials were made, and the relationships between their molecular structures and phase behaviour are discussed with the aid of molecular modelling at the B3LYP/6-31G* level of density functional theory.

We show how a simple bilayer system that combines a layer of undoped BaTiO3 (BT) with a second layer of Ba0.975Na0.025Ti0.975Nb0.025O3 (2.5NNBT) can be used to improve the temperature coefficient of capacitance (TCC) of BaTiO3-based materials for capacitor applications. The bilayer system emulates the volume ratio between a conventional core and shell phase microstructure allowing a simple resource efficient approach to optimise the system for low TCC. Optimisation was achieved with a volume ratio of 0.67 2.5NNBT with 0.33 BT and results in a TCC of ±6% over the temperature range ∼25 to 125 °C whilst maintaining a permittivity of εr ∼ 3000 and low dielectric loss.

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