Aging-Induced, Defect-Mediated Double Ferroelectric Hysteresis Loops and Large Recoverable Electrostrains in Mn-Doped Orthorhombic KNbO3-Based Lead-Free Ceramics

2010-2011 > Academic research: refereed > Chapter in an edited book (author

Reduced ferroelectric coercivity in multiferroic Bi 0.825 Nd 0.175 FeO 3 thin film

Bi 0.825 Nd 0.175 FeO 3 ͑BNFO͒ thin film is grown on Pt/ TiO 2 / SiO 2 / Si substrate by pulsed laser deposition, and its multiferroic properties are compared with those of BiFeO 3 ͑BFO͒ thin film. With limited Fe 2+ ions and its twinborn oxygen vacancies, both samples show low dielectric losses of Ͻ0.026 at 100 Hz and high maximum ferroelectric polarizations of ϳ34 C/cm 2 . The ferroelectric coercive field of BNFO is reduced by ϳ40%, reaching a low value of 235 kV/ cm, compared to that of BFO due to the increased ratio of 180°and curved ferroelectric domains to total ferroelectric domains and better nucleation of the ferroelectric domains at the BNFO/Pt interface. The Raman scattering spectra confirm that the ferroelectric polarizations of both samples originate in the stereochemical activity of the Bi lone electron pair. Weak ferromagnetism is observed in both samples as a result of the limited amount of Fe 2+ ions and ␥-Fe 2 O 3 impurity