Претрага
5 items
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Sinteza i strukturna karakterizacija mikroporoznih arsenata i fosfata
Sabina Z. Kovač (2015-09-28)Predmet rada i istraživanja ove doktorske disertacije su sinteza i strukturnekarakteristike novih kristalnih arsenata i fosfata koji sadrže Mg, K, Ca, Mn, Fe, Co, Ni,Cu, Zn, Sr, Ba i druge katjone. U strukturama arsenata i fosfata, AsO4- i PO4-tetraedrinajčešće se vezuju sa tetraedarski ili oktaedarski koordinisanim katjonima prelaznihmetala formirajući otvorene strukture (slojeve ili 3D mreže) sa širokim opsegomrazličitih topologija. U šupljinama ili porama u obliku povezanih ili nepovezanihkanala, tunela, kaveza i međuslojnog prostora mogu se ugraditi različiti vanmrežni joni(obično ...... od toga samo desetak relativno čestih. Oko 60 % arsenskih minerala čine arsenati, oko 20 % sulfidi i sulfosoli, oko 10 % oksidi, a ostatak čine arseniti, arsenidi, samorodni As i legure (Bowell and Parshley, 2001). Arsenati predstavljaju veliku grupu minerala u okviru koje su često prisutni čvrsti ...
... strukturnog tipa i opšte formule T12[T2(OH)6], gde je T1 = Sr2+, Ba2+, T2 = Cu2+, Zn2+. Ključne reči: hidrotermalna sinteza, mikroporozna jedinjenja, arsenati, fosfati, rendgenska strukturna analiza Naučna oblast: Geo‒nauke Uža naučna oblast: Kristalografija UDK broj: 548:542.913[553.641+549 ...
... poliedarski i topološki prikaz struktura i njihovu klasifikaciju. U današnje vreme istaknuto mesto u strukturnim istraživanjima zauzimaju arsenati i fosfati koji imaju porozne strukture (Gao et al., 1996; Cheetham et al., 1999; Harrison, 2001; Murugavel et al., 2008 i tamo navedena literatura) ...Sabina Z. Kovač. "Sinteza i strukturna karakterizacija mikroporoznih arsenata i fosfata" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2015-09-28)
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Water in the Alluaudite Type-Compounds: Synthesis, Crystal Structure and Magnetic Properties of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H,□)0.5(H2O,H3O)0.5]2x+
In this study, a new cobalt arsenate belonging to the alluaudite supergroup compounds with the general formula of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H, )0.5(H2O,H3O)0.5]2x+ (denoted as CoAsAllu) was synthesized under hydrothermal conditions. Its crystal structure was determined by a room-temperature single-crystal X-ray diffraction analysis: space group C2/c, a = 11.6978(8), b = 12.5713(7), c = 6.7705(5) Å, b = 113.255(5)◦, V = 914.76(11) Å3, Z = 2 for As6H8Co6O25. It represents a new member of alluaudite-like protonated arsenates and the first alluaudite-like phase ...супергрупа алуаудита, арсенати прелазних метала, хидротермална синтеза, кристална структура, хидратисани хидрокси-арсенати, стехиометрија, магнетна својстваTamara Đorđević, Ljiljana Karanović, Marko Jagodič, Zvonko Jagličić. "Water in the Alluaudite Type-Compounds: Synthesis, Crystal Structure and Magnetic Properties of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H,□)0.5(H2O,H3O)0.5]2x+" in Minerals, MDPI AG (2021). https://doi.org/10.3390/min11121372
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An update on the mineral-like Sr-containing transition metal arsenates
Tamara Đorđević, Ljiljana Karanović (2021)We report on the crystal structures of three novel synthetic SrM-arsenates (M = Ni and Fe3+), isostructural or structurally related to the minerals from tsumcorite, carminite and brackebuschite groups. They were synthesised under mild hydrothermal conditions and further characterised using single-crystal X-ray diffraction (SXRD), scanning electron microscopy with energy dispersive spectroscopy (SEMEDS) and Raman spectroscopy. SXRD and SEM-EDS yielded formulae: (I) SrNi2(AsO4)2·2H2O, (II) Sr1.4Fe3+ 1.6(AsO4)2(OH)1.6 and (III) SrFe3+(AsO4)(AsO3OH). All three structures are built up of slightly distorted MO6 octahedra ...арсенати метала, кристална структура, дифракција рендгенских зрака на монокристалима, хидротермална синтеза, Раманова спектроскопија, релевантна једињења у животној средини, арсенeochemistry and PetrologyTamara Đorđević, Ljiljana Karanović. "An update on the mineral-like Sr-containing transition metal arsenates" in Mineralogical Magazine, Mineralogical Society (2021). https://doi.org/10.1180/mgm.2021.41
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A new copper(II) arsenate, Na2Cu3(AsO3OH)4·4H2O containing discrete [Cu3O12]18− units: Synthesis, crystal structure and magnetic properties
Single crystals of the new disodium tricopper(II) tetrakis(hydrogenarsenate(V)) tetrahydrate, Na2Cu3(AsO3OH)4·4H2O were grown under hydrothermal conditions. The compound was characterized by room-temperature single-crystal X-ray diffraction, SEM-EDS analysis, Raman spectroscopy and magnetic susceptibility measurements. Na2Cu3(AsO3OH)4·4H2O represents a new layered structure-type [space group P21/c, a = 8.7089(17), b = 9.7452(19), c = 9.3353(19) Å, β = 92.63(3)°, V = 791.4(3) Å3, Z = 4]. The layers are normal to [100] and are composed of the isolated Cu3O12 units interconnected by AsO3OH coordination ...Na2Cu3(AsO3OH)4•4H2O, хидротермална синтеза, кристална структура, хидрирани хидрокси-арсенати, магнетна својстваTamara Đorđević, Ljiljana Karanović, Zvonko Jagličić. "A new copper(II) arsenate, Na2Cu3(AsO3OH)4·4H2O containing discrete [Cu3O12]18− units: Synthesis, crystal structure and magnetic properties" in Journal of Solid State Chemistry, Elsevier BV (2018). https://doi.org/10.1016/j.jssc.2018.05.024
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Three new Sr-bearing arsenates, hydrothermally synthesized in the system SrO–MO–As2O5–H2O (M2+ = Mg, Cu, Zn)
Tamara Đorđević, Ljiljana Karanović (2018)During systematic research on the mineral-related synthetic arsenates, with particular focus on their structural and spectroscopic classification, three new Sr-containing arsenates Sr2Mg(AsO4)2· 2H2O (1), Sr2Zn4(AsO4)4·H2O (2) and Sr2Cu7(AsO4)6 (3) have been synthesized under low-temperature hydrothermal conditions in the system SrO MO As2O5 H2O (M 2þ = Mg, Zn, Cu). Their crystal structures were determined using room-temperature single-crystal X-ray diffraction data and refined to the following R-values: 1– R1 = 0.025; 2– R1 = 0.030; 3– R1 = 0.035. Compounds ...стронцијум, арсен, арсенати, кристална структура, дифракција рендгенских зрака на монокристалима, хидротермална синтеза, Раманска спектроскопијаTamara Đorđević, Ljiljana Karanović. "Three new Sr-bearing arsenates, hydrothermally synthesized in the system SrO–MO–As2O5–H2O (M2+ = Mg, Cu, Zn)" in European Journal of Mineralogy, Schweizerbart (2018). https://doi.org/10.1127/ejm/2018/0030-2749