Band gaps of piezoelectric/piezomagnetic phononic crystal with magneto-electro-elastic interlayer

Abstract

Laminate piezoelectric (PE)/piezomagnetic (PM) composites consisting of alternating PE and PM layers can facilitate the conversion of energy between electric and magnetic fields, i.e., they possess the magneto-electric (ME) coupling effects, which recently has attracted much attention due to the huge potential applications in the field of high technology. The PE/PM phononic crystal is an ideal material for manufacturing high-tech precision parts such as resonator components, magnetoelectric sensors, weak magnetic field detectors, electric field tunable filters and magnetic field probes. In the practical applications, the adhesive interfaces of PE/PM phononic crystals are prone to deformation and failure during their use, because of the big difference between PE and PM material. In this paper, the magneto-electro-elastic (MEE) interlayer of magneto-electro-mechanical coupling is introduced into the PE/PM phononic crystal. The thickness of the MEE interlayer, the volume fraction of the piezoelectric material in the MEE interlayer and the type of the piezoelectric materials in the MEE interlayer are changed separately, with the thickness of the unit cell kept at a fixed value. The dispersion relation between the k and the is obtained by using the transfer matrix method and Bloch theorem. The influence of MEE interlayer on the band gap characteristics of PE/PM phononic crystal is studied by the dispersion relation diagram. The results show that as the thickness of the MEE interlayer increases, the central frequency of the band gaps shifts toward a higher frequency and the width of band gap becomes wider. As the volume fraction of the piezoelectric material increases, the center frequency and the width of the first band gap decrease. However, the width of the second band gap increases, and the width of the third band gap remains unchanged. The type of piezoelectric material in the MEE interlayer has an obvious influence on both the width and the central frequency of the band gaps. The effect of MEE interlayer on the central frequency of band gap of PE/PM phononic crystal is more significant in the high frequency region than in the low frequency region. Therefore, the width and central frequency of the band gaps can be adjusted to a certain extent by adding different MEE interlayers into the phononic crystal structure when designed.