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Abstract
The structural and magnetic properties of the Al-doped La0.75Sr0.25Mn0.5Cr0.5−xAlxO3−δ (x = 0.0, 0.1, 0.2, 0.3) were investigated by X-ray powder diffraction, neutron powder diffraction and magnetization measurements. Rietveld refinement of the diffraction data confirms that the compounds crystallize in rhombohedral symmetry (space group, R-3C). Unit cell volume decreases with increasing concentration of Al at the B-site. Upon cooling from room temperature, we have observed multiple magnetic phase transitions, i.e. paramagnetic (PM), ferromagnetic (FM), antiferromagnetic (AFM) and spin–glass (SG), in the samples. A low temperature magnetic hysteresis study demonstrates the presence of ferromagnetic domains for all compositions. The antiferromagnetic transition temperature decreases with the Al-doping AC susceptibility measurements at 97 Hz and 1 Oe show SG behaviors with a spin-freezing temperature close to 50 K for all samples. The in-phase ac susceptibility (χ/) decreases in magnitude and spin–glass transition (TSG) increase toward higher temperature with increasing frequency. The spin–glass behavior accompanied by the anomalous magnetic transitions is due to the competing interactions between FM and AFM. The results also shows that a part of the samples lose magnetic order to form a SG state accompanied by an AFM state at low temperature.
Original language | English |
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Pages (from-to) | 2482-2490 |
Number of pages | 9 |
Journal | Materials Research Bulletin |
Volume | 48 |
Issue number | 7 |
Early online date | 15 May 2013 |
DOIs | |
Publication status | Published - 7 Jul 2013 |
Keywords
- Ceramics
- Magnetic materials
- Neutron powder diffraction
- Magnetic properties
- DOPED MANGANITES
- PHASE-SEPARATION
- METALLIC STATE
- RARE-EARTH
- CR
- MAGNETORESISTANCE
- BEHAVIOR
- LA0.67CA0.33MN0.9FE0.1O3
- PR0.5CA0.5MNO3
- SUBSTITUTION
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Dive into the research topics of 'Spin–glass transition in La0.75Sr0.25Mn0.5Cr0.5−xAlxO3−δ perovskites'. Together they form a unique fingerprint.Projects
- 2 Finished
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Material for high Temp FCT EP/E064248/1: Materials for High Temperature Fuel Cell Technology
Irvine, J. T. S. (PI), Cassidy, M. (CoI), Connor, P. A. (CoI), Savaniu, C. D. (CoI) & Tao, S. (CoI)
1/01/08 → 31/12/12
Project: Standard
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Fellowship EP/D07259X/1 Fuelling the Fut: Fuelling the future: From materials to new energy conversion systems
Irvine, J. T. S. (PI)
1/09/06 → 31/08/11
Project: Fellowship