Department of Electrical and Computer Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA.
Nanoscale. 2017 Sep 14;9(35):13052-13059. doi: 10.1039/c7nr03504g.
Magnetoelastoelectric coupling in an engineered biphasic multiferroic nanocomposite enables a novel magnetic field direction-defined propagation control of terahertz (THz) waves. These core-shell nanoparticles are comprised of a ferromagnetic cobalt ferrite core and a ferroelectric barium titanate shell. An assembly of these nanoparticles, when operated in external magnetic fields, exhibits a controllable amplitude modulation when the magnetic field is applied antiparallel to the THz wave propagation direction; yet the same assembly displays an additional phase modulation when the magnetic field is applied along the propagation direction. While field-induced magnetostriction of the core leads to amplitude modulation, phase modulation is a result of stress-mediated piezoelectricity of the outer ferroelectric shell.
在工程双相多铁性纳米复合材料中，磁弹电耦合实现了太赫兹（THz）波的新型磁场方向定义传播控制。这些核壳纳米粒子由铁磁钴铁氧体核和铁电钛酸钡壳组成。当这些纳米粒子组装体在外部磁场中工作时，当磁场沿与 THz 波传播方向相反的方向施加时，会表现出可控制的振幅调制；然而，当磁场沿传播方向施加时，同一组装体显示出额外的相位调制。虽然核心的场致磁致伸缩导致了振幅调制，但相位调制是外部铁电壳的应力介导压电性的结果。
