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Title: Magnetic properties of proton irradiated BiFeO{sub 3}

Abstract

The crystal structure and magnetic properties of BiFeO{sub 3} samples, proton-irradiated with 0, 10, and 20 pC/{mu}m{sup 2}, were investigated with x-ray diffraction (XRD), vibrating sample magnetometer, and Moessbauer spectroscopy measurements. From the Rietveld refinement analysis of the XRD patterns, the crystal structure of BiFeO{sub 3} is determined to be rhombohedral with the space group of R3c. We have observed the decrease in the lattice constant and oxygen occupancy with proton irradiation. The magnetization hysteresis (M-H) curves show the appearance of the weak ferromagnetic behavior in the proton irradiated BiFeO{sub 3} samples. The Moessbauer spectra of proton irradiated BiFeO{sub 3} samples at 295 K were analyzed with two-sextets (B{sub 1} and B{sub 2}) and doublet. From the isomer shift ({delta}) values, ionic states were determined to be Fe{sup 3+}. Compared to non-irradiated sample, having the antiferromagnetic area ratio (two-sextets) of 45.47, 54.53% the antiferromagnetic and paramagnetic area ratios (doublet) of 10 and 20 pC/{mu}m{sup 2} proton irradiated BiFeO{sub 3} samples are 41.36, 51.26, and 7.38% and 41.03, 50.90, and 8.07%, respectively. Our experimental observation suggests that the increase in the paramagnetic area ratio is due to the disappearance of superexchange interaction, resulted from the removal of the oxygen with protonmore » irradiation. Also, the appearance of the weak ferromagnetic behavior is caused by the breaking of the antiferromagnetic coupling.« less

Authors:
; ;  [1]
  1. Department of Physics, Kookmin University, Seoul 136-702 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22102409
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 113; Journal Issue: 17; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; ANTIFERROMAGNETIC MATERIALS; ANTIFERROMAGNETISM; BISMUTH COMPOUNDS; FERRITES; FERROMAGNETIC MATERIALS; INTERACTIONS; ISOMER SHIFT; LATTICE PARAMETERS; MAGNETIC PROPERTIES; MAGNETIZATION; MOESSBAUER EFFECT; PARAMAGNETISM; PHYSICAL RADIATION EFFECTS; PROTON BEAMS; SPACE GROUPS; SPECTRA; TRIGONAL LATTICES; VIBRATING SAMPLE MAGNETOMETERS; X-RAY DIFFRACTION

Citation Formats

Han, Seungkyu, Jin Kim, Sam, and Sung Kim, Chul. Magnetic properties of proton irradiated BiFeO{sub 3}. United States: N. p., 2013. Web. doi:10.1063/1.4795616.
Han, Seungkyu, Jin Kim, Sam, & Sung Kim, Chul. Magnetic properties of proton irradiated BiFeO{sub 3}. United States. doi:10.1063/1.4795616.
Han, Seungkyu, Jin Kim, Sam, and Sung Kim, Chul. 2013. "Magnetic properties of proton irradiated BiFeO{sub 3}". United States. doi:10.1063/1.4795616.
@article{osti_22102409,
title = {Magnetic properties of proton irradiated BiFeO{sub 3}},
author = {Han, Seungkyu and Jin Kim, Sam and Sung Kim, Chul},
abstractNote = {The crystal structure and magnetic properties of BiFeO{sub 3} samples, proton-irradiated with 0, 10, and 20 pC/{mu}m{sup 2}, were investigated with x-ray diffraction (XRD), vibrating sample magnetometer, and Moessbauer spectroscopy measurements. From the Rietveld refinement analysis of the XRD patterns, the crystal structure of BiFeO{sub 3} is determined to be rhombohedral with the space group of R3c. We have observed the decrease in the lattice constant and oxygen occupancy with proton irradiation. The magnetization hysteresis (M-H) curves show the appearance of the weak ferromagnetic behavior in the proton irradiated BiFeO{sub 3} samples. The Moessbauer spectra of proton irradiated BiFeO{sub 3} samples at 295 K were analyzed with two-sextets (B{sub 1} and B{sub 2}) and doublet. From the isomer shift ({delta}) values, ionic states were determined to be Fe{sup 3+}. Compared to non-irradiated sample, having the antiferromagnetic area ratio (two-sextets) of 45.47, 54.53% the antiferromagnetic and paramagnetic area ratios (doublet) of 10 and 20 pC/{mu}m{sup 2} proton irradiated BiFeO{sub 3} samples are 41.36, 51.26, and 7.38% and 41.03, 50.90, and 8.07%, respectively. Our experimental observation suggests that the increase in the paramagnetic area ratio is due to the disappearance of superexchange interaction, resulted from the removal of the oxygen with proton irradiation. Also, the appearance of the weak ferromagnetic behavior is caused by the breaking of the antiferromagnetic coupling.},
doi = {10.1063/1.4795616},
journal = {Journal of Applied Physics},
number = 17,
volume = 113,
place = {United States},
year = 2013,
month = 5
}
  • BiFeO{sub 3} layers with various thicknesses were fabricated on La{sub 0.7}Sr{sub 0.3}MnO{sub 3} covered SrTiO{sub 3} substrates by a laser molecular-beam epitaxy system. The ferromagnetic transition temperature (T{sub c}) and magnetic coercive field (H{sub c}) of BiFeO{sub 3}/La{sub 0.7}Sr{sub 0.3}MnO{sub 3} heterostructures are larger than those of the La{sub 0.7}Sr{sub 0.3}MnO{sub 3} film. With increasing the thickness of the BiFeO{sub 3} layer, T{sub c}, H{sub c}, and ferroelectric coercive field of the BiFeO{sub 3}/La{sub 0.7}Sr{sub 0.3}MnO{sub 3} heterostructures decrease, while the dielectric permittivity, remanent polarization, and resistance ratio of the ON and OFF states increase. The variations of the magneticmore » and electric properties with the thickness could be due to the effects of the epitaxial strain and the interface layer.« less
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  • The effects of neutron and proton dose on the magnetic properties of a reactor pressure vessel (RPV) steel were investigated. The coercivity and maximum induction increased in two stages with respect to neutron dose, being nearly constant up to a dose of 1.5 x 10{sup {minus}7} dpa, followed by a rapid increase up to a dose of 1.5 x 10{sup {minus}5} dpa. The coercivity and maximum induction in the proton irradiated specimens also showed a two stage variation with respect to proton dose, namely a rapid increase up to a dose of 0.2 x 10{sup {minus}2} dpa, then a decreasemore » up to 1.2 x 10{sup {minus}2} dpa. The Barkhausen noise (BN) amplitude in neutron irradiated specimens also varied in two stages in a reverse manner, the transition at the same dose of 1.5 x 10{sup {minus}7} dpa. The BN amplitude in proton irradiated specimens decreased by 60% up to 0.2 x 10{sup {minus}2} dpa followed by an increase up to 1.2 x 10{sup {minus}2} dpa. The results were in good accord with the one dimensional domain wall model considering the density of defects and wall energy.« less
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