Reduced ferroelectric coercivity in multiferroic Bi0.825Nd0.175FeO3 thin film
Reduced ferroelectric coercivity in multiferroic Bi0.825Nd0.175FeO3 thin film
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DOI：
10.1063/1.2423228
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发表时间：
2007-01
影响因子：
3.2
通讯作者：
G. Yuan;S. Or;H. Chan;Zu-liang Liu
中科院分区：
文献类型：
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作者：
G. Yuan;S. Or;H. Chan;Zu-liang Liu
采用脉冲激光沉积法在铂/二氧化钛/二氧化硅/硅衬底上生长了Bi0.825Nd0.175FeO(BNFO)薄膜，并与BiFeO(BFO)薄膜的多铁性进行了比较。由于Fe~(2+)离子及其孪生氧空位的存在，两种样品在100赫兹的介电损耗均为<；0.026，最大铁电极化强度为∼34μC/cm~2。与BFO相比，BNFO的铁电矫顽场降低了40%，仅为235KV/cm，这是因为BNFO的铁电畴与总的铁电畴之比增加了180°，并且在BNFO/Pt界面上形成了更好的铁电畴。拉曼散射光谱证实，两种样品的铁电极化都源于铋孤电子对的立体化学活性。由于Fe~(2+)离子和γ-Fe_2O_3杂质的数量有限，两种样品都观察到了较弱的铁磁性。
Bi0.825Nd0.175FeO3 (BNFO) thin film is grown on Pt∕TiO2∕SiO2∕Si substrate by pulsed laser deposition, and its multiferroic properties are compared with those of BiFeO3 (BFO) thin film. With limited Fe2+ ions and its twinborn oxygen vacancies, both samples show low dielectric losses of <0.026 at 100Hz and high maximum ferroelectric polarizations of ∼34μC∕cm2. The ferroelectric coercive field of BNFO is reduced by ∼40%, reaching a low value of 235kV∕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 Fe2+ ions and γ‐Fe2O3 impurity.