2010/03/10 by Indu Dhiman, I. Dhiman, A. Das +7
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Condensed matter physics #Electron #Ferromagnetism #Magnetic and transport properties of perovskites and related materials #Materials science #Neutron scattering #Optics #Physics #Polaron #Rare-earth and actinide compounds #Scattering #Superlattice #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.81.104423
13 pages, 12 figures, To appear in Physical Review B
arxiv created 2010/03/10 · openalex publication_date 2010/03/30 · arxiv updated 2015/05/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The short-range-ordered magnetic correlations have been studied in half-doped La0.5Ca_0.5\ensuremath-xSrxMnO3 (x=0.1, 0.3, and 0.4) compounds by polarized neutron scattering technique. On doping Sr2+ for Ca2+ ion, these compounds with x=0.1, 0.3, and 0.4 exhibit CE-type, mixture of CE-type and A-type, and A-type antiferromagnetic ordering, respectively. Magnetic diffuse scattering is observed in all the compounds above and below their respective magnetic ordering temperatures and is attributed to magnetic polarons. The correlations are primarily ferromagnetic in nature above TN, although a small antiferromagnetic contribution is also evident. Additionally, in samples x=0.1 and 0.3 with CE-type antiferromagnetic ordering, superlattice diffuse reflections are observed indicating correlations between magnetic polarons. On lowering temperature below TN, the diffuse scattering corresponding to ferromagnetic correlations is suppressed and the long-range-ordered antiferromagnetic state is established. However, the short-range-ordered correlations indicated by enhanced spin-flip scattering at low Q coexist with long-range-ordered state down to 3 K. In x=0.4 sample with A-type antiferromagnetic ordering, superlattice diffuse reflections are absent. Additionally, in comparison to x=0.1 and 0.3 sample, the enhanced spin-flip scattering at low Q is reduced at 310 K, and as temperature is reduced below 200 K, it becomes negligibly low. The variation in radial correlation function, g(r) with temperature indicates rapid suppression of ferromagnetic correlations at the first nearest neighbor on approaching TN. Sample x=0.4 exhibits growth of ferromagnetic phase at intermediate temperatures (\ensuremath∼200 K). This has been further explored using small-angle neutron scattering and neutron depolarization techniques.