Bulletin of materials science | |
Synthesis, structural and ferromagnetic properties of La1â€�?�ð�?�¥Kð‘¥MnO3 (0.0â‰�? ð‘�? 0.25) phases by solution combustion method | |
C Shivakumara1  Manjunath B Bellakki1  | |
[1] Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India$$Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, IndiaSolid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India$$ | |
关键词: Perovskite; XRD; crystal structure; electrical properties; magnetic materials.; | |
DOI : | |
学科分类:材料工程 | |
来源: Indian Academy of Sciences | |
【 摘 要 】
We describe the solution combustion synthesis and characterization of La1â€�?�ð�?��?Kð‘�?MnO3 (0.0 â‰�? ð‘�? â‰�? 0.25) perovskite phases, which is a low temperature initiated, rapid route to prepare metal oxides. As-synthesized compounds are amorphous in nature; crystallinity was observed on heating at 800°C for 5 min. Structural parameters were determined by the Rietveld refinement method using powder XRD data. Parent LaMnO3 compound crystallizes in the orthorhombic structure (space group ð‘ƒð�?�ð�?��?�ð�?��?, No. 62). Potassium substituted compounds were crystallized with rhombohedral symmetry (space group ð‘�?�â€�?3c, No. 167). The ratio of the Mn3+/Mn4+ was determined by the iodometric titration. The Fourier transform infrared spectrum (FTâ€�?�IR) shows two absorption bands for Mnâ€�?�O stretching vibration (ðœˆs mode), Mnâ€�?�Oâ€�?�Mn deformation vibration (ðœˆb mode) around 600 cm-1 and 400 cm-1 for the compositions, ð‘�? = 0.0, 0.05 and 0.10. Four-probe electrical resistivity measurements reveal a composition controlled metal to insulator transition (ð‘�??Mâ€�?�I}}$), the maximum ð‘�??Mâ€�?�I was observed for the composition La0.85K0.15MnO3 at 287 K. Room temperature vibrating sample magnetometer data indicate that for the composition up to ð‘�? = 0.10, the compounds are paramagnetic whereas composition with ð‘�? = 0.15, 0.20 and 0.25 show magnetic moments of 27, 29 and 30 emu/g, respectively.
【 授权许可】
Unknown
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