Phonon and Magneto-electric ordering in Gallium Ferrite multiferroic
ORAL
Abstract
Multiferroic materials with transition temperatures around room temperature are of current interest due to their technological importance and novel applications. Herein we report phonons, magnetic and ferroelectric ordering in perovskite GaFeO3 using magnetization, dielectric and Raman scattering measurements. Single phase GFO ceramics, prepared by solid state reaction shows orthorhombic phase (space group C2v9) studied under xrd pattern. Temperature dependent magnetization behaviors studied in between 5-395 K at both field-cooled and zero-field-cooled conditions identify Néel transition (TN) at around 225 K. Evidence of spin-glass like magnetic ordering is observed at low temperature. Phonon frequencies and thier line-widths exhibit anomalies across TN. The changes in phonon frequencies observed in Raman scattering are explained based on spin-phonon coupling in the low temperature ferrimagnetic phase. Examination of the phonon behavior indicates that three phonon anharmonicity process is dominant over other higher order processes. The temperature and frequency dependent dielectric measurements indicated a dielectric anomaly at around 590 K suggesting that the system exhibits ferroelectric relaxor behavior. The detailed experimental results and their analysis will be presented.
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Presenters
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Sita Dugu
- Department of Physics, University of Puerto-Rico