Wang Ping, Zhang Elric, Toledo Dennis, Smith Isadora Takako, Navarrete Brayan, Furman Nathaniel, Hernandez Alexandro Franco, Telusma Mackenson, McDaniel Dwayne, Liang Ping, Khizroev Sakhrat
Department of Electrical and Computer Engineering, University of Miami, Coral Gables, Florida 33146, United States.
Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33174, United States.
Nano Lett. 2020 Aug 12;20(8):5765-5772. doi: 10.1021/acs.nanolett.0c01588. Epub 2020 Jul 14.
Magnetoelectric coefficient values of above 5 and 2 V cm Oe in 20 nm CoFeO-BaTiO and NiFeO-BaTiO core-shell magnetoelectric nanoparticles were demonstrated. These colossal values, compared to 0.1 V cm Oe commonly reported for the 0-3 system, are attributed to (i) the heterostructural lattice-matched interface between the magnetostrictive core and the piezoelectric shell, confirmed through transmission electron microscopy, and (ii) in situ scanning tunneling microscopy nanoprobe-based ME characterization. The nanoprobe technique allows measurements of the ME effect at a single-nanoparticle level which avoids the charge leakage problem of traditional powder form measurements. The difference in the frequency dependence of the ME value between the two material systems is owed to the Ni-ferrite cores becoming superparamagnetic in the near-dc frequency range. The availability of novel nanostructures with colossal ME values promises to unlock many new applications ranging from energy-efficient information processing to nanomedicine and brain-machine interfaces.
在20纳米的CoFeO-BaTiO和NiFeO-BaTiO核壳磁电纳米颗粒中，展示出了磁电系数值分别高于5和2 V cm Oe。与0-3系统通常报道的0.1 V cm Oe相比，这些巨大的值归因于：（i）通过透射电子显微镜确认的磁致伸缩核与压电壳之间的异质结构晶格匹配界面；（ii）基于原位扫描隧道显微镜纳米探针的磁电表征。纳米探针技术允许在单纳米颗粒水平上测量磁电效应，这避免了传统粉末形式测量中的电荷泄漏问题。两种材料系统之间磁电值频率依赖性的差异归因于镍铁氧体核在近直流频率范围内变成超顺磁性。具有巨大磁电值的新型纳米结构的可用性有望开启许多新应用，从节能信息处理到纳米医学和脑机接口。
