COMPLEX SILVER VANADATE AS LUMINOFOR IN RED AND NEAR-INFRARED REGION OF LUMINESCENCE AND METHOD OF ITS OBTAINING

FIELD: chemistry. SUBSTANCE: invention can be used in manufacturing of indicators and sensors of ionising and infrared radiation. Initial mixture of ingredients is prepared, wt %: AgNO₃ - 39.91?42.28; MCO₃ - 12.46?17.3; where M - Ca or Sr; V₂O₅ - 42.74?45.26; thoroughly mixing said components in presence of alcohol. Then it is heated to 300-350°C and expose at said temperature for 2-3 hours. After that it is heated again to 480-500°C and expose at said temperature for 95-105 hours. Powder is briquetted and thermally processed at 490-500°C during 38-42 hours. Complex silver vanadate which is obtained has composition Ag₂M(VO₃)4, where M - Ca or Sr, and luminesces in red and near-infrared region up to 840-850 nm. EFFECT: obtaining silver vanadate. 2 cl, 2 dwg, 2 ex.Изобретение может быть использовано при изготовлении индикаторов и сенсоров ионизирующего и инфракрасного излучения. Готовят исходную смесь ингредиентов, мас.%: AgNO₃ - 39,91?42,28; MCO₃ - 12,46?17,3; где М - Са или Sr; V₂O₅ - 42,74?45,26; тщательным перемешиванием указанных компонентов в присутствии спирта. Затем ее нагревают до 300-350°С с выдержкой при этой температуре 2-3 ч. После этого снова нагревают до 480-500°С с выдержкой при этой температуре 95-105 ч. Порошок брикетируют и термообрабатывают при 490-500°С в течение 38-42 ч. Полученный сложный ванадат серебра имеет состав Ag₂M(VO₃)₄, где М - Са или Sr, и люминесцирует в красной и ближней инфракрасной области вплоть до 840-850 нм. 2 н.п. ф-лы, 2 ил

Sr2GaScO5, Sr10Ga6Sc4O25, and SrGa0.75Sc0.25O2.5 : a Play in the Octahedra to Tetrahedra Ratio in Oxygen-Deficient Perovskites

Three different perovskite-related phases were isolated in the SrGa1-xScxO2.5 system: Sr2GaScO5, Sr10Ga6Sc4O25, and SrGa0.75Sc0.25O2.5, Sr2GaScO5 (x = 0.5) crystallizes in a brownrnillerite-type structure [space group (S.G.) Icmm, a = 5.91048(5) angstrom, b = 15.1594(1) angstrom, and c = 5.70926(4) angstrom] with complete ordering of Sc3+ and Ga3+ over octahedral and tetrahedral positions, respectively. The crystal structure of Sr10Ga6Sc4O25 (x = 0.4) was determined by the Monte Carlo method and refined using a combination of X-ray, neutron, and electron diffraction data [S.G. I4(1)/a, a = 17.517(1) angstrom, c = 32.830(3) angstrom]. It represents a novel type of ordering of the B cations and oxygen vacancies in perovskites. The crystal structure of Sr10Ga6Sc4O25 can be described as a stacking of eight perovskite layers along the c axis ...[-(Sc/Ga)O-1.6-SrO0.8-(Sc/Ga)O-1.8-SrO0.8-](2 center dot center dot center dot) Similar to Sr2GaScO5, this structure features a complete ordering of the Sc3+ and Ga3+ cations over octahedral and tetrahedral positions, respectively, within each layer. A specific feature of the crystal structure of Sr10Ga6Sc4O25 is that one-third of the tetrahedra have one vertex not connected with other Sc/Ga cations. Further partial replacement of Sc3+ by Ga3+ leads to the formation of the cubic perovskite phase SrGa0.75Sc0.25O2.5 (x = 0.25) with a = 3.9817(4) angstrom. This compound incorporates water molecules in the structure forming SrGa0.75Sc0.25O2.5 center dot xH(2)O hydrate, which exhibits a proton conductivity of similar to 2.0 x 10(-6) S/cm at 673 K

Sr₂GaScO₅, Sr₁₀Ga₆Sc₄O₂₅, and SrGa_0.75Sc_0.25O_2.5: a Play in the Octahedra to Tetrahedra Ratio in Oxygen-Deficient Perovskites

Three different perovskite-related phases were isolated in the SrGa_1–<i>x</i>Sc_<i>x</i>O_2.5 system: Sr₂GaScO₅, Sr₁₀Ga₆Sc₄O₂₅, and SrGa_0.75Sc_0.25O_2.5. Sr₂GaScO₅ (<i>x</i> = 0.5) crystallizes in a brownmillerite-type structure [space group (S.G.) <i>Icmm</i>, <i>a</i> = 5.91048(5) Å, <i>b</i> = 15.1594(1) Å, and <i>c</i> = 5.70926(4) Å] with complete ordering of Sc³⁺ and Ga³⁺ over octahedral and tetrahedral positions, respectively. The crystal structure of Sr₁₀Ga₆Sc₄O₂₅ (<i>x</i> = 0.4) was determined by the Monte Carlo method and refined using a combination of X-ray, neutron, and electron diffraction data [S.G. <i>I</i>4₁/<i>a</i>, <i>a</i> = 17.517(1) Å, <i>c</i> = 32.830(3) Å]. It represents a novel type of ordering of the B cations and oxygen vacancies in perovskites. The crystal structure of Sr₁₀Ga₆Sc₄O₂₅ can be described as a stacking of eight perovskite layers along the <i>c</i> axis ...[−(Sc/Ga)­O_1.6–SrO_0.8–(Sc/Ga)­O_1.8–SrO_0.8−]₂.... Similar to Sr₂GaScO₅, this structure features a complete ordering of the Sc³⁺ and Ga³⁺ cations over octahedral and tetrahedral positions, respectively, within each layer. A specific feature of the crystal structure of Sr₁₀Ga₆Sc₄O₂₅ is that one-third of the tetrahedra have one vertex not connected with other Sc/Ga cations. Further partial replacement of Sc³⁺ by Ga³⁺ leads to the formation of the cubic perovskite phase SrGa_0.75Sc_0.25O_2.5 (<i>x</i> = 0.25) with <i>a</i> = 3.9817(4) Å. This compound incorporates water molecules in the structure forming SrGa_0.75Sc_0.25O_2.5·<i>x</i>H₂O hydrate, which exhibits a proton conductivity of ∼2.0 × 10^–6 S/cm at 673 K