Synthesis, Structure, and Investigation of Bismuth Niobate Doped by Alkaline-Earth Elements

Polycrystalline samples with general formula Bi3

Thermodynamic database for multicomponent oxide systems. Preparation, Structure and Physicochemical Properties of La0.95Bi0.05Mn1–yCuyO3+δ (у = 0.1 – 0.4) and Composites with Bi2O3‑Based Electrolytes

Received: 02.06.2018. Accepted: 19.07.2018. Published: 30.07.2018.Samples of La0.95Bi0.05Mn1–yCuyO3+δ (у = 0.1 – 0.4) were prepared by solid-state synthesis. Additionally, the sample with nominal composition La0.95Bi0.05Mn0.7Cu0.3O3+δ was obtained using citrate-nitrate method. It was determined by X-ray diffraction analysis that the compounds have rhombohedral (space group R3C) or orthorhombic (space group Pbnm) structure, depending on the composition. Single-phase compounds are synthesized at у = 0.1; 0.2. The investigation using scanning electron microscope showed that the grain sizes for the samples sintered using different techniques are close to each other because of the high calcination temperature. For the sample with orthorhombic structure the phase transition into rhombohedral one was found around 390 °С by means of dilatometry. Thermal expansion coefficient of the sample La0.95Bi0.05Mn0.7Cu0.3O3+δ is equal to 6·10–6 K–1 (T 390 °C). The composite materials of substituted lanthanum manganites with Bi4V1.7Fe0.3O11–δ and Bi7Nb1.8Zr0.2O15.5–δ solid electrolytes were obtained at 650 °C. The electrical conductivity values for the latter one are by three orders of magnitude higher than for pure bismuth niobate.The work was carried out within the framework of the state task of the Ministry of education and science of the Russian Federation № 4.2288.2017 / PCh

Preparation, Structure and Physicochemical Properties of La0.95Bi0.05Mn1-yCuyO3+δ (у=0.1-0.4) and Composites with Bi2O3-Based Electrolytes

Samples of La0.95Bi0.05Mn1-yCuyO3+δ (у=0.1-0.4) were prepared by solid-state synthesis. Additionally, the sample with nominal composition La0.95Bi0.05Mn0.7Cu0.3O3+δ was obtained using citrate-nitrate method. It was determined by X-ray diffraction analysis that the compounds have rhombohedral (space group R-3c) or orthorhombic (space group Pbnm) structure, depending on the composition. Single-phase compounds are synthesized at у=0.1; 0.2. The investigation using scanning electron microscope showed that the grain sizes for the samples sintered using different techniques are close to each other because of the high calcination temperature. For the sample with orthorhombic structure the phase transition into rhombohedral one was found around 390 °С by means of dilatometry. Thermal expansion coefficient of the sample La0.95Bi0.05Mn0.7Cu0.3O3+δ is equal to 6·10-6 K-1 (T 390 °C). The composite materials of substituted lanthanum manganites with Bi4V1.7Fe0.3O11-δ and Bi7Nb1.8Zr0.2O15.5-δ solid electrolytes were obtained at 650 °C. The electrical conductivity values for the latter one are by three orders of magnitude higher than for pure bismuth niobate

A PHASE PHORMATION OF NIOBIUM-CONTAINING BISMUTH TUNGSTATES

Complex oxides based on Bi2O3 are often used as solid-state electrolytes for electrochem-ical devices. Therefore, the purpose of this work is to obtain solid solutions of bismuth tung-states substituted with niobium and to study their physicochemical properties.Работа выполнена при финансовой поддержке Министерства науки и высшего образования РФ (задание АААА-А20-120061990010-7)

SYNTHESIS AND CHARACTERIZATION OF Bi22W5-ХMХO48- δ (M= Mn, Fe, Co)

The samples with general formula Bi22W5-xMxO48-δ (M= Mn, Fe, Co; х=0-0.2) have been synthesized by solid state method. It was found that the samples crystallize with cubic structure. Bi22W5-xCoxO48-δ has the highest values of electroconductivity

SYNTHESIS AND STUDIES PHYSICOCHEMICAL PROPERTIES OF VANADIUM SUBSTITUTED BISMUTH TUNGSTATES

The solid solutions of Bi23W4-xVxO46.5-δ, Bi22W4.5-xVxO47.25-δ, Bi22W5-xVxO48-δ (х=0; 0.3) with cubic structure have been prepared by solid state method. Thermal expansion coefficient is equal to 13×10-6 °C-1. The electroconductivity of the substituted samples is higher than for the matrix ones.Работа выполнена в рамках государственного задания Министерства образования и науки Российской Федерации № 4.2288.2017/4.6