Temperature independent low loss dielectrics based on quaternary pyrochlore oxides

Thermal Expansion, XPS Spectra, and Structural and Electrical Properties of a New Bi2NiTa2O9 Pyrochlore

“…Synthetic pyrochlores have been attracting scientific attention for decades because of their wide range of practically useful properties. Compounds with pyrochlore structure can exhibit magnetic, piezoelectric, and electro-optical properties; they are known as superconductors, multiferroics, photocatalysts, and dielectrics. − Pyrochlore-based materials are used in solid-state devices as thermistors, thick-film resistors, and communication elements and are used as components of ceramic forms for radioactive waste. Bismuth-based pyrochlores, due to their excellent dielectric properties, low sintering temperature, chemical inertness with respect to Ag-electrodes, and composition-adjustable temperature coefficient of capacitance, prove to be extremely promising materials for manufacturing multilayered ceramic capacitors and electronic devices for the microwave range. − Two interpenetrating weakly interacting sublattices of A 2 O and B 2 O 6 are distinguished in the cubic structure of pyrochlore A 2 B 2 O 7 ( Fd 3̅ m ). , The B 2 O 6 basic structure octahedrons arranged around the diamond grid points form a vertex-linked tetrahedral framework.…”

Ab Initio and Experimental Insights on Structural, Electronic, Optical, and Magnetic Properties of Cr-Doped Bi2Ti2O7

“…Pyrochlore compounds are interesting due to their different physical properties, which depend on the chemical composition and the applied method of synthesis. The wide range of the cationic radius ratio 1.46 < r (A 3+ )/ r (B 4+ ) < 1.80 (“pyrochlore field” for A 3+ 2 B 4+ 2 O 7 ), the possibility of the substitution either A- or B-site atoms, , and stability with the presence of vacancies , allow designing new pyrochlore compounds with miscellaneous properties . Bismuth titanate pyrochlore Bi 2 Ti 2 O 7 (BTO) is such an outstanding example. − New doped BTO pyrochlores may be potentially used as dielectric materials at room temperatures, − as mixed electronic-ionic conductors at intermediate temperatures for developing electrochemical devices, as luminescence compounds, − and in photocatalytic applications. − …”

“…Pyrochlore compounds are interesting due to their different physical properties, which depend on the chemical composition and the applied method of synthesis. The wide range of the cationic radius ratio 1.46 < r(A 3+ )/r(B 4+ ) < 1.80 ("pyrochlore field" for A 3+ 2 B 4+ 2 O 7 ), 1 the possibility of the substitution either A-or B-site atoms, 2,3 and stability with the presence of vacancies 4,5 allow designing new pyrochlore compounds with miscellaneous properties. 6 Bismuth titanate pyrochlore Bi 2 Ti 2 O 7 (BTO) is such an outstanding example.…”

“…3 ,4 A 2g term of ground state, S 1 = S 2 = 3/2) obtained by the way including total spin S and of the twoparticle system with S 1 and S 2 spins and energy of the state E(J, S) is expressed as76 …”

Dielectric Properties Bi₂MgTaNbO₉

“…197-206. DOI: 10.17516/1998-2836-0228ВведениеНеиссякаемый на протяжении многих лет интерес к синтетическим пирохлорам обусловлен проявлением ими широкого спектра практически полезных свойств, таких как сверхпроводниковые, электрооптические, фотокаталитические и диэлектрические свойства[1,2]. Висмутсодержащие пирохлоры привлекают пристальное внимание благодаря своим превосходным диэлектрическим свойствам -высокой диэлектрической проницаемости, малым значениям диэлектрических потерь и температурного коэффициента емкости, а также низкой температуре спекания и химической инертности по отношению к Ag-электродам.…”