@article { ISI:000269638800052, title = {Magnetic characteristics of nanocrystalline multiferroic BiFeO3 at low temperatures}, journal = {Physical Review B}, volume = {80}, number = {6}, year = {2009}, month = {AUG}, pages = {064423}, publisher = {AMER PHYSICAL SOC}, address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}, abstract = {

The magnetic characteristics of nanocrystalline BiFeO3 with average crystallite sizes of similar to 50 and similar to 100 nm are evaluated by studying the temperature and field dependence of magnetization at low temperatures. Different properties such as magnetization, coercivity, and remanence show evidence for changes in the magnetic properties associated with the phase transitions at low temperatures, reported from Raman studies. Detailed field-cooled and zero-field-cooled magnetization measurements show that the likely origin of the changes in the magnetic characteristics is from the changes in the domain structure.

}, keywords = {bismuth compounds, coercive force, crystallites, magnetic domains, magnetic transitions, Multiferroics, Nanostructured materials, Raman spectra, remanence}, issn = {1098-0121}, doi = {10.1103/PhysRevB.80.064423}, author = {Vijayanand, S. and Mahajan, Mangesh B. and Potdar, H. S. and Joy, Pattayil Alias} } @article { ISI:000265933700042, title = {Origin of high room temperature ferromagnetic moment of nanocrystalline multiferroic BiFeO3}, journal = {Applied Physics Letters}, volume = {94}, number = {18}, year = {2009}, month = {MAY}, pages = {182507}, publisher = {AMER INST PHYSICS}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

Single phase nanocrystalline BiFeO3 of average crystallite size similar to 25 nm with very high magnetization at room temperature is synthesized by an autocombustion method. Magnetic measurements above room temperature show deviation between field cooled and zero field cooled magnetization below 645 K, the Neel temperature (T-N) of the bulk material, indicating intrinsic nature of ferromagnetism. However, observation of a broad magnetic transition above T-N of BiFeO3 and extended up to 800 K suggests the presence of Fe3O4 as a possible magnetic impurity phase. Evidence for the presence of Fe3O4 is obtained from detailed analysis of the powder x-ray diffraction pattern.

}, keywords = {bismuth compounds, Combustion synthesis, crystallites, ferromagnetic materials, high-temperature effects, magnetic impurities, Magnetic moments, Magnetisation, Multiferroics, Nanostructured materials, Neel temperature, X-ray diffraction}, issn = {0003-6951}, doi = {10.1063/1.3132586}, author = {Vijayanand, S. and Potdar, H. S. and Joy, Pattayil Alias} } @article { ISI:000307039700023, title = {Enhanced magnetic parameters in the morphotropic phase boundary region of nanocrystalline multiferroic Bi1-xLaxFeO3}, journal = {Solid State Communications}, volume = {152}, number = {16}, year = {2012}, month = {AUG}, pages = {1609-1612}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Antiferromagnetic multiferroic BiFeO3 shows ferromagnetic characteristics by simultaneous substitution of Bi by La and decrease in the particle size to nanometer dimensions. Large changes in saturation and remnant magnetization, magnetic susceptibility at low and high fields, along with some anomalous changes in the magnetic transition temperature are observed in nanocrystalline Bi1-xLaxFeO3 system for 0.1 \<= x \<= 0.2. This compositional region corresponds to the morphotropic phase boundary (MPB) region separating the rhombohedral and orthorhombic phases, and the effect is similar to that observed in many ferroelectric systems. The present observation of enhanced ferromagnetic parameters in the MPB region of the nanocrystalline multiferroic La substituted BiFeO3 system, combined with the known ferroelectric characteristics, is suitable for future device applications. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Bismuth ferrite, magnetic properties, Multiferroics, Nanocrystalline materials}, issn = {0038-1098}, doi = {10.1016/j.ssc.2012.05.011}, author = {Thakuria, P. and Joy, Pattayil Alias} }