Naslov
Direct molecular-to-material pathway: a preparation of mixed oxides from heteropolynuclear oxalate complex

Autori
Popović, Jasminka ; Jurić, Marijana ; Šantić, Ana ; Molčanov, Krešimir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts , Twenty-first Slovenian-Croatian Crystallographic Meeting / Leban, Ivan ; Lah, Nina - Ljubljana, 2012, 27-27

Skup
Twenty-first Slovenian-Croatian Crystallographic Meeting

Mjesto i datum
Pokljuka, Slovenija, 14.06.2012. - 17.06.2012

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
XRD; Polymorphs; MOFs; direct patway

Sažetak
A novel complex {;Ba2(H2O)5[NbO(C2O4)3]HC2O4};•H2O (1) has been prepared and characterized by single- crystal XRD, IR and thermal analysis. The ability of 1 to act as a single-source precursor for the formation of bimetallic oxides has been explored by thermal analysis and XRPD. The thermal treatment of 1 at the chosen temeprature (600- 1200 °C) followed by cooling, results in the formation of the mixed-metal Ba5Nb4O15 and/or Ba4Nb2O9 oxide phases. The Ba5Nb4O15, as the major crystalline oxide phase, forms at ~700 °C. Three stable Ba4Nb2O9 polymorphs have been isolated: already well known hexagonal α-form [1-3] and orthorhombic γ-form [1-3], and so far unrealized hexagonal δ-polymorph, having 6H-perovskite structure (space group ). Heating 1 at 1135 °C and then cooling to RT leads to formation of α- Ba4Nb2O9, while the same procedure at 1175 °C results in the crystallization of another two polymorphs, γ-Ba4Nb2O9 and δ-Ba4Nb2O9. Electrical measurements were performed on samples prepared by pelleting milled single crystals of 1 and heated to chosen temperatures. The results of conductivity measurements were completely comparable with those reported for Ba4Nb2O9 ceramics prepared via multiple reheating steps, typical for conventional ceramics preparations [3]. Therefore, we believe that proposed synthetic procedure deserves additional attention since the benefit of “two in one” approach - one-step preparation of the desired oxide phase which is already in a form suitable for conductivity measurements - was successfully established.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA