Structural and magnetic properties in the self-doped perovskite manganites with nominal composition La0.7Sr0.3−xMnO3−δ

✍ Scribed by S.P. Liu; G.D. Tang; Z.Z. Li; D.H. Ji; Y.F. Li; W. Chen; D.L. Hou

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 675 KB
• Volume: 406
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2010.12.016

✦ Synopsis

Perovskite manganites with nominal composition La 0.7 Sr 0.3 À x MnO 3 À d (0.00 r x r 0.20) have been prepared by the sol-gel method with the highest heat treatment temperature being 1073 K. The XRD patterns indicate that when the doping level is x r 0.10 the samples have only a single phase, with the R3 ¯c perovskite structure, while for x 4 0.10, the samples have two phases with the R3 ¯c perovskite being the dominant phase and Mn 3 O 4 being the second phase. A quantitative analysis and Rietveld fitting of the X-ray powder diffraction data indicate that on the basis of the thermal equilibrium theory of crystal defects there are Mn 2 + ions at the A sites and Mn 3 + plus Mn 4 + ions at the B sites in the ABO 3 perovskite phase. The curves of magnetization versus applied magnetic field at 10 K showed that the magnetic moments of the Mn 2 + ions at the A sites are antiparallel to those of the Mn 3 + and Mn 4 + ions at the B sites.