The effect of multidirectional bias magnetic fields on the converse magnetoelectric response of multiferroic concentric composite ring

Abstract

A composite multiferroic ring was characterized under two orthogonal bias magnetic fields while electrically loaded near resonance to measure the circumferential converse magnetoelectric (CME) response. The composite multiferroic structure consisted of an inner magnetostrictive Terfenol-D ring with an axially aligned preferred magnetocrystalline axis bonded to a radially polarized outer piezoelectric poled lead zirconate titanate ring to form a concentric ring structure. A single uniform bias magnetic field was varied from zero to beyond magnetic saturation while the composite ring's axial alignment was changed from perpendicular to parallel with respect to the bias magnetic field direction. The change in the ring orientation thus subjected the ring to two orthogonal bias magnetic fields, whose strengths were calculated based on the orientation angle. The overall CME behavior was found to be largely correlated with the perpendicular magnetic field strength assisted with the shape anisotropy of the ring structure favoring magnetization along the longest axis. Nonetheless, the parallel magnetic field had a notable contribution to the CME response by enhancing the magnetization in the preferred axial direction and activating other unique magnetocrystalline axes. In all, the CME behavior with respect to two orthogonal bias magnetic fields is characterized by an interplay of magnetocrystalline and shape anisotropies bolstered by the parallel and perpendicular magnetic fields.

Insights into the displacement field in magnetoelectric composites

“…Second, the experimental results were found to be in an excellent agreement with the numerical nodal displacement resulting from the bonding contact boundary condition. The latter closely resembles the physical contact boundary conditions observed in the experiment since the cylinders were bonded using silver epoxy (Chavez et al, 2016;Newacheck et al, 2018), hence preventing the relative movement at the interface diameter. Since the frequency resolution of the experiment was coarser than that reported in the computational data, Gaussian approximation was used to refine the resolution and yielding an experimental resonance peak at 30.875 kHz, which compares very well to the numerically calculated resonance frequency of 31.185 kHz, that is, less than 1% difference.…”

Noncontact spatiotemporal strain mapping of composite multiferroic cylinders

“…Finally, the vibrational displacements were induced by subjecting the piezoelectric cylinder to a radial AC electric field (30 kHz) using a waveform generator (Agilent 33210A) and a high voltage amplifier (Trek PZD700A) at a level of 20 kV/m. The selection of the amplitude and frequency of the electric field was based on previous studies reported in Newacheck et al (2018), Chavez et al (2016) and Youssef et al (2017a).…”

“…Analytical models predict the concentric cylinder geometry to exhibit a giant magnetoelectric response due to the curvature enhancing the strain transfer between material layers (Wang et al 2010a). Our group has extensively studied the CME response of the concentric cylinder structure using experimental, analytical, and computational analyses (Newacheck et al 2018;Chavez et al 2016;Youssef et al 2020a). Specifically, we have experimentally investigated the effect of the bias magnetic field direction, electric field direction, and bonding methods, while analytically explored the effect of mechanical boundary conditions, and developed validated computational models (Newacheck et al 2018;Chavez et al 2016;Youssef et al 2020a, b).…”

“…Our group has extensively studied the CME response of the concentric cylinder structure using experimental, analytical, and computational analyses (Newacheck et al 2018;Chavez et al 2016;Youssef et al 2020a). Specifically, we have experimentally investigated the effect of the bias magnetic field direction, electric field direction, and bonding methods, while analytically explored the effect of mechanical boundary conditions, and developed validated computational models (Newacheck et al 2018;Chavez et al 2016;Youssef et al 2020a, b). In the previous efforts, not only we investigated and reported the overall response, i.e., the converse magnetoelectric coefficient, but also, we thoroughly studied the behavior of each of the constituents such as the direction of polarization of the piezoelectric cylinder (Youssef et al 2017a) as well as the magnetostriction response of Terfenol-D (Youssef et al 2017b).…”

Synthesis, optical, and magnetic properties of six‐layered Aurivillius bismuth ferrititanate

“…Consequently, the components have important electrical, magnetic, optical, and photochemical applications . Bi‐based compounds have drawn a lot of attention because for their potential application as novel photocatalysts, in which the lone pair electrons of Bi 3+ ere are often found to possess hybridized band structures . Especially, Aurivillius compounds have been widely reported because of its special layer perovskite atom arrangements and favourable optical band structure .…”