کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1332229 979034 2011 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Phase formation, crystal structures and magnetic properties of perovskite-type phases in the system La2Co1+z(MgxTi1−x)1−zO6
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Phase formation, crystal structures and magnetic properties of perovskite-type phases in the system La2Co1+z(MgxTi1−x)1−zO6
چکیده انگلیسی

Perovskite-type cobaltates in the system La2Co1+z(MgxTi1−x)1−zO6 were studied for z=0≤x≤0.6 and 0≤x<0.9, using X-ray and neutron powder diffraction, electron diffraction (ED), magnetic susceptibility measurements and X-ray absorption near-edge structure (XANES) spectroscopy. The samples were synthesised using the citrate route in air at 1350 °C. The space group symmetry of the structure changes from P21/n via Pbnm to R3¯c with both increasing Mg content and increasing Co content. The La2Co(MgxTi1−x)O6 (z=0) compounds show anti-ferromagnetic couplings of the magnetic moments for the Co below 15 K for x=0, 0.1 and 0.2. XANES spectra show for the compositions 0≤x≤0.5 a linear decrease in the L3/(L3+L2) Co–L2,3 edge branching ratio with x, in agreement with a decrease of the average Co ion spin-state, from a high-spin to a lower-spin-state, with decreasing nominal Co2+ ion content.

XRPD patterns for perovskite compounds along the lines La2Co(MgxTi1−x)O6 and La2Co1+z(Mg0.5Ti0.5)1−zO6.Figure optionsDownload as PowerPoint slideResearch Highlights
► Tuning of the oxidation state of Co in the perovskite system La2Co1+z(MgxTi1−x)1−zO6, z=0≤x≤0.6 and 0≤x<0.9.
► XANES study of the oxidation state of Co in the perovskite system La2Co1+z(MgxTi1−x)1−zO6, z=0≤x≤0.6 and 0≤x<0.9.
► Phase relations in the perovskite system La2Co1+z(MgxTi1−x)1−zO6, z=0≤x≤0.6 and 0≤x<0.9.
► Magnetic properties in the perovskite system La2Co1+z(MgxTi1−x)1−zO6, z=0≤x≤0.6 and 0≤x<0.9.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Solid State Chemistry - Volume 184, Issue 1, January 2011, Pages 177–190
نویسندگان
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