Multiferroic properties of Tb-doped BiFeO3 nanowires
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Nanoscale, multifunctional, multiferroic materials possess strong magnetoelectric coupling (ME), open exciting multitudinous ways for designing future nanoelectronic and spintronic device applications. Bulk nanowires (100 nm), pure, and Tb-doped BiFeO3 multiferroic nanowires (20 nm) have been synthesized by colloidal dispersion template-assisted technique. The effects of Tb-doping and size of synthesized nanowires on structural, electrical, magnetic, dielectric, and magnetodielectric properties have been investigated. X-ray diffraction study reveals that doping of Tb in BiFeO3 nanowires leads to structural transformation from rhombohedral to orthorhombic. X-ray photoemission analysis confirms the +3 oxidation state of Fe and high purity of samples. Bulk nanowires exhibit antiferromagnetic characteristics, whereas the Tb-doped BiFeO3 nanowires show ferromagnetic character. Moreover, with increase in Tb concentration, the saturation magnetization increases. Temperature-dependent magnetization study suggests their size-dependent ferro and ferri-magnetic behavior. Polarization versus electric field (P–E) study reveals that pure BiFeO3 nanowires possess elliptical loop; however, doping of Tb results in rectangular loop— portentous good ferroelectric properties. All synthesized samples exhibit frequency-dependent dielectric constant which decreases with increase in frequency and remains fairly constant at higher frequencies. Leakage current density decreases with increase in Tb concentration, and has been found to be three orders of magnitude less than those of bulk BiFeO3 nanowires. The ME coupling in synthesized nanowires was estimated by measuring magnetodielectric. A very high value of ME, 7.2 %, has been found for 15 % Tb-doped BiFeO3 nanowires. In this communication, we, for the first time, report new cue on size-dependent Tb-doped BiFeO3 nanowires, which may be further used to explore its technological device applications.
KeywordsNanowires Ferroelectricity Multiferroics Spin spiral cycloid Magnetoelectric effect
One of the authors, Gurmeet Singh Lotey, gratefully acknowledges the Department of Science and Technology (DST), Government of India, for awarding him the INSPIRE (Innovation in Science Pursuit for Inspired Research) fellowship to carry out this research work.
- Cao G (2004) Nanostructures and nanomaterials: synthesis, properties, and applications. World Scientific, Imperial College Press, LondonGoogle Scholar
- Hench LL, West JL (1990) Principles of electronic Ceramic. Wiley, New YorkGoogle Scholar
- Lotey GS, Kumar S, Verma NK (2012) Fabrication and electrical characterization of highly ordered copper nanowires. Appl Nanosci 2(7):13Google Scholar
- Rothery WH, Smallman RE, Haworth CW (1969) The structure of metals and alloys. Metals and Metallurgy Trust of the Institute of Metals and the Institution of Metallurgists, LondonGoogle Scholar