Correlation between structural, electrical and magnetic properties of GdMnO3 bulk ceramics

The Use of Malonate Coordination Polymers with CuII and BaII Atoms for Barium Cuprate Preparation

“…The phase composition of the solid product is determined by the thermolysis conditions. Under thermogravimetric experiment conditions, mixtures of BaCuO 2 , BaCO 3 and CuO phases were the end products from all of the complexes 1-3, 5 and 6. An increase in the barium cuprate content in the thermolysis product can be achieved by changing the process atmosphere, increasing the feed rate of external gas to the process zone, and introducing an isothermal segment at the final temperature of thermolysis.…”

“…The structure of 3 also contains two uncoordinated water molecules involved in hydrogen bonding for each {Ba 3 Cu 3 (Bumal) 6 (H 2 O) 11 } unit.…”

“…For a long time, lithium cobaltate has been mainly obtained by direct solid-phase synthesis at high temperatures from lithium oxide or hydroxide and cobalt carbonate or oxide, [1,2] GdMnO 3 is obtained by a solidphase reaction from the corresponding oxides followed by grinding and rebriquetting, [3] and barium cuprate is still synthesized by the sintering of oxides for many hours. [4,5] Similarly, classical solid-phase syntheses in an oxygen atmosphere are used to obtain polycrystalline samples of TbMn 2 O 5 , DyMn 2 O 5 , [6] and GdBaCo 2 O 5+x , which is a promising cathode material for solid-electrolyte high-temperature fuel cells.…”

“…[7] Moreover, in comparison with solidphase syntheses, sol-gel technologies for the preparation of complex oxides from metal salts (nitrates or acetates) in the presence of polybasic carboxylic acids make it possible achieve higher sample homogenization, shorten the heat treatment time and decrease the synthesis temperature for a complex oxide with a required structure. For example, the superconductive YBa 2 Cu 3 O 7-x phase can be obtained by decomposition of mixed solutions of acetates or trifluoroacetates of the corresponding metals followed by homogenizing annealing, [8] and polycrystalline samples of GdCoO 3 and SmCoO 3 can be obtained from cobalt nitrate and a nitrate of the appropriate rare-earth element. [9] Lately, complex oxide materials have often been obtained from heterometallic complexes with organic ligands.…”

“…500°C) and it is possible to obtain oxide nanoparticles at relatively low temperatures. For example, monodispersed CoFe 2 O 4 was obtained by the thermolysis of the molecular complexes [Fe 2 CoO(Piv) 6 (HPiv) 3 ] and [Co 4 Fe 2 O 2 (Piv) 10 (MeCN) 2 ] (Piv = trimethylacetic acid anion) at 260-300°C in organic solvents in the presence of oleylamine or oleic acid. [11] The feasibility of obtaining thin Cu-Co and Ni-Cu oxide films from molecular heterometallic precursors with cubanelike structure has been demonstrated.…”