The nature of the mechanical-strain-mediated converse magnetoelectric effect (CME) is studied in multiferroic composites of single-crystal-like thin films of nickel ferrite (NFO) and polycrystalline lead zirconate tit...
详细信息
The nature of the mechanical-strain-mediated converse magnetoelectric effect (CME) is studied in multiferroic composites of single-crystal-like thin films of nickel ferrite (NFO) and polycrystalline lead zirconate titanate (PZT). Ferrite films of thickness 0.45–1 micron are prepared by pulsed-laser deposition on lattice-matched (100)- and (110)-oriented substrates of magnesium gallate (MGO) and cobalt gallate (CGO) that result in elimination of antiphase boundaries and magnetic parameters comparable to bulk single crystals. Ferromagnetic resonance under a static electric field E is utilized for studies of CME effects in composites of PZT and NFO films on the substrates. The in-plane static magnetic field H is applied along the principal crystallographic axes of the ferrite film to study its influence on the CME. The E-induced magnetoelectric (ME) anisotropy field HME is estimated from ferromagnetic resonance data based on the shift in resonance frequency with E in order to determine the ME constant A=HME/E. In composites with NFO films on (110)-oriented substrates (i) the ME coupling is stronger for films on CGO possibly due to a better lattice match and weaker substrate clamping than for films on MGO, (ii) A values are the highest for H || [1,−1,0], and (iii) a negative A value is inferred for H || [001]. For composites with NFO on (100)-oriented substrates the strongest ME coupling is measured for H along the [001] direction. A model for CME that takes into consideration both compressive and bending deformation in the composites is developed and the results of the theory are in agreement with both the sign and magnitude of the measured ME coefficient A. The results of the studies presented here indicate the potential for use of the composites in self-biased E-tunable microwave devices.
The sine-cosine algorithm (SCA) is a new population-based meta-heuristic algorithm. In addition to exploiting sine and cosine functions to perform local and global searches (hence the name sine-cosine), the SCA introd...
详细信息
Globally coal-fired power plants are still predominantly utilised for production of electrical energy. The efficiency of a coal-fired power plant is greatly influenced by the performance of the boiler. In turn, the bo...
详细信息
The aim of this work is to develop an artificial neural network (ANN) based model for accurately predicting the daily global solar irradiation in the city of Fez. The potential of the developed model is verified and a...
详细信息
A method of identifying runout of an active magnetic bearing at standstill and low speed is presented. The on-line current bias injection method found in literature is improved, but is still found to converge too slow...
详细信息
Demand response will be an important tool as non-dispatchable generation is added to the grid. Swimming pool filtration pumps are a promising appliance for the grid operator to control because, unlike air conditioners...
Demand response will be an important tool as non-dispatchable generation is added to the grid. Swimming pool filtration pumps are a promising appliance for the grid operator to control because, unlike air conditioners, their time of operation can be shifted by a day without affecting their primary role. Although many customers set and forget the timer settings, this paper studies smart meter data and demonstrates that many change the settings frequently. A 'care index' is proposed that quantifies how much a customer appears to care about the precise timing of pump operation, which indicates how willing they are likely to be to relinquish control to the grid operator.
We study electrohydrodynamic convection (EHC) patterns in twisted nematic liquid crystal (TNCL) cells with an initial homeotropic alignment. In addition, we demonstrate switching characteristics due to the transition ...
详细信息
We study electrohydrodynamic convection (EHC) patterns in twisted nematic liquid crystal (TNCL) cells with an initial homeotropic alignment. In addition, we demonstrate switching characteristics due to the transition between the 90° and −90∘ twisted states. The pattern formations are similar to those obtained in a parallel-aligned nontwisted liquid crystal cell. Calculations of the free energy in an initially, homeotropically aligned TNLC in an electric field demonstrate that the energy barrier between the two states decreases with the increase of the electric field. The mutual transition is caused by the fluctuating flow at the dynamic scattering mode 2, where the energy barrier between the two states is reduced by applying a strong electric field. These properties may be employed for the development of a redirectable dynamic lenticular lens, as an extended version of the dynamic lenticular lens using EHC. The transition between the two states caused by EHC is reversible, and the convection roll pattern of the Williams domain rotates by 90° at each transition.
To model the interdependent couplings of multiple topics, we develop a set of rules for opinion updates of a group of agents. The rules are used to design or assign values to the elements of interdependent weighting m...
详细信息
暂无评论