Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS) , Virginia Tech , Blacksburg , Virginia 24061 , United States.
Advanced Devices & Sustainable Energy Laboratory , Virginia Tech , Blacksburg , Virginia 24061 , United States.
Nano Lett. 2018 May 9;18(5):2835-2843. doi: 10.1021/acs.nanolett.7b05248. Epub 2018 Apr 10.
Heteroepitaxial magnetoelectric (ME) composites are promising for the development of a new generation of multifunctional devices, such as sensors, tunable electronics, and energy harvesters. However, challenge remains in realizing practical epitaxial composite materials, mainly due to the interfacial lattice misfit strain between magnetostrictive and piezoelectric phases and strong substrate clamping that reduces the strain-mediated ME coupling. Here, we demonstrate a nonstrain-mediated ME coupling in PbZrTiO (PZT)/LaSrMnO (LSMO) heteroepitaxial composites that resolves these challenges, thereby, providing a giant magnetodielectric (MD) response of ∼27% at 310 K. The factors driving the magnitude of the MD response were found to be the magnetoresistance-coupled dielectric dispersion and piezoelectric strain-mediated modulation of magnetic moment. Building upon this giant MD response, we demonstrate a magnetic field sensor architecture exhibiting a high sensitivity of 54.7 pF/T and desirable linearity with respect to the applied external magnetic field. The demonstrated technique provides a new mechanism for detecting magnetic fields based upon the MD effect.
异质外延磁电（ME）复合材料有望开发新一代多功能器件，如传感器、可调谐电子设备和能量收集器。然而，在实现实用的外延复合材料方面仍然存在挑战，主要是由于磁致伸缩相与压电相之间的界面晶格失配应变和强烈的基底夹持，这降低了应变介导的 ME 耦合。在这里，我们在 PbZrTiO（PZT）/LaSrMnO（LSMO）异质外延复合材料中展示了一种非应变介导的 ME 耦合，该复合材料解决了这些挑战，从而提供了在 310 K 时约为 27%的巨大磁电（MD）响应。发现驱动 MD 响应幅度的因素是磁电阻耦合介电色散和压电应变介导的磁矩调制。基于这种巨大的 MD 响应，我们展示了一种磁场传感器结构，其灵敏度高达 54.7 pF/T，并且相对于所施加的外部磁场具有良好的线性度。所展示的技术提供了一种基于 MD 效应检测磁场的新机制。
