Magnetoelectric Multilayer Gallium Arsenide–Nickel–Tin–Nickel Structures

Abstract

The production process is considered, and the results of a theoretical and experimental study of the magnetoelectric effect in a multilayer structure obtained by galvanic deposition of alternating layers of nickel and tin onto a gallium arsenide substrate are presented. It is experimentally found that the use of tin as an intermediate layer in a multilayer structure decreases the mechanical stresses arising from the inconsistency of the lattice parameters at the nickel/gallium arsenide interface, which makes it possible to obtain high-quality multilayer structures with the thickness of the nickel layer of about 100 μm. On the basis of the joint solution of the equations of elastodynamics and electrostatics for the magnetostriction, piezoelectric, and buffer layers, an expression for the magnetoelectric voltage coefficient is obtained. It is theoretically shown and experimentally confirmed that the frequency dependence of the magnetoelectric coefficient has a resonant character, and the value of the resonant frequency gradually decreases with the growth in the number of layers from the value corresponding to the natural oscillation frequency of a plate made of gallium arsenide, approaching the value corresponding to the natural oscillation frequency of a plate consisting of a layer of nickel and tin, the thickness of which is equal to double the thickness of the layer of nickel. It is experimentally found that, in the region of electromechanical resonance, the obtained structures have a high quality factor Q ≅ 1000, which is more than 20-fold higher than the quality factor of the magnetoelectric structures fabricated by gluing, and have good adhesion between the layers. These structures are promising for creating devices based on the magnetoelectric effect.