Naslov
Commensurate superstructures in the [(Ca/Sr)2Cu2O3][CuO2]x≈√2 composite crystal

Autori
Milat, Ognjen ; Salamon, Krešimir ; Tomić, Silvia ; Vuletić, Tomislav ; Ivek Tomislav

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings 10th Multinational Congress on Microscopy 2011 / Falcieri, Elisabetta - Urbino : Societa Italiana Scienze Microscopiche (SISM), 2011, 41-42

Skup
MCM 2011 10th Multinational Congress on Microscopy

Mjesto i datum
Urbino, Italija, 04.09.2011. - 09.09.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
composite crystal; modulated structure; electron diffraction

Sažetak
An electron microscopy and diffraction study of the nominal (Sr/Ca)14Cu24O41 compound is presented. We propose an alternative formula: [(Ca/Sr)2Cu2O3][CuO2]x≈√2 that better represents this incommensurate composite crystal structure. Namely, composite crystals are a class of long range ordered solids that are composed of two or more subsystems, each one with its own lattice and cell symmetry. For a series of compounds with widely used formula (Sr/Ca)14Cu24O41 (Ca for Sr isostructural substitution), the constituting subsystems are: (i) Sr/Ca)2Cu2O3 -“ladders”, and ; (ii) CuO2 -“chains”[1][2]. The lattices of these subsystems have common a and b parameters while being incommensurate along c-axis. With increasing Ca-substitution the cLd/cChratio varies from 1.44 for pure Sr14Cu24O41, to 1.416 for highly substituted Sr0.6Ca13.4Cu24O41[3]. This is accompanied by charge (hole) redistribution between the CuO2-chains and the Cu2O3-ladders. More holes reside in the CuO2-chains for higher cLd/cCh ratio [4].

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA