Origin of spin-glass and exchange bias in La{sub 1∕3}Sr{sub 2∕3}FeO{sub 3−γ} nanoparticles

Journal Article · Fri Mar 21 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4868685· OSTI ID:22271214

Silva, R. B. da; Araújo, J. H. de ^[1]; Soares, J. M. ^[2]; Machado, F. L. A. ^[3]

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1. Departamento de Física Teórica e Experimental, UFRN, Natal (Brazil)
2. Departamento de Física, UERN, Mossoró, RN (Brazil)
3. Departamento de Física, UFPE, Recife, PE (Brazil)

The structure and the magnetic properties of nanopowdered samples of La{sub 1∕3}Sr{sub 2∕3}FeO{sub 3−γ} with average particles size d in the range of 67-367 nm prepared by a sol-gel method were investigated in detail. The samples were characterized by X-ray diffraction, scanning electron microscopy, specific heat, Mössbauer spectroscopy, ac susceptibility, and magnetization measurements. Exchange bias with vertical magnetization shift was found in all samples. Charge ordering and antiferromagnetism were observed close to 200 K for large particles (d ≥ 304 nm) samples, while for particles with intermediated and smaller values (d ≤ 156 nm) a cluster-glass like behaviour and a short range charge ordering were seen near 115 K and 200 K, respectively. The spin-glass like and exchange bias behaviour in nanopowdered samples of La{sub 1∕3}Sr{sub 2∕3}FeO{sub 3−γ} are associated to compact Fe{sup 3+} antiferromagnetic (AF) clusters caused by an oxygen deficiency, which was found to be higher in the samples with the smallest average particles sizes. The effect of exchange bias and vertical magnetization shifts are explained by a simple model involving the interaction of one AF phase with a canted AF phase.

• OSTI ID: 22271214
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
ABSORPTION SPECTROSCOPY
ANTIFERROMAGNETISM
FERRITES
LANTHANUM COMPOUNDS
MAGNETIC SUSCEPTIBILITY
MAGNETIZATION
MOESSBAUER EFFECT
NANOSTRUCTURES
PARTICLE SIZE
PARTICLES
POWDERS
SCANNING ELECTRON MICROSCOPY
SOL-GEL PROCESS
SPECIFIC HEAT
SPIN GLASS STATE
STRONTIUM COMPOUNDS
X-RAY DIFFRACTION