Investigation of element-specific and bulk magnetism, electronic and crystal structures of La{0.70}Ca{0.30}Mn{1-x}Cr{x}O{3}
| Autor: | Terashita, H., Cezar, J. C., Ardito, F. M., Bufaical, L. F., Granado, E. |
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| Rok vydání: | 2011 |
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| Zdroj: | Phys. Rev. B 85, 104401 (2012) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.85.104401 |
| Popis: | The magnetic interactions in La{0.70}Ca{0.30}Mn{1-x}Cr{x}O{3} (x = 0.15, 0.50 and 0.70) are investigated by x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD), high-resolution x-ray powder diffraction, and bulk magnetization measurements. XAS in the Mn and Cr L{2,3} edges support stable single valent Cr{3+} ions and a varying Mn valence state with x, while the O K edge XAS spectrum reveals local maxima in the O 2p density of states close to the Fermi level due to mixing with Mn and Cr 3d states. A robust antiferromagnetic state is found for x=0.70 below TN = 258 K. For x=0.15, combined XMCD and bulk magnetization measurements indicate a fully polarized ferrimagnetic state for the Mn and Cr spins below Tc=224 K. For x=0.50, a reduced ferrimagnetic component dominated by Mn spins is present below Tc=154 K. No evidence of lattice anomalies due to cooperative charge and orbital orderings is found by x-ray diffraction for all samples. The magnetic properties of this system are rationalized in terms of a competition of ferromagnetic Mn-Mn double exchange and antiferromagnetic Cr-Cr and Cr-Mn superexchange interactions. Comment: 25 pages, 9 figures |
| Databáze: | arXiv |
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