Wave band gaps in two-dimensional piezoelectric/piezomagnetic phononic crystals

Abstract

a b s t r a c tIn this paper, the elastic wave propagation in phononic crystals with piezoelectric and piezomagnetic inclusions is investigated taking the magneto-electro-elastic coupling into account. The electric and magnetic fields are approximated as quasi-static. The band structures of three kinds of piezoelectric/piezomagnetic phononic crystals-CoFe 2 O 4 /quartz, BaTiO 3 /CoFe 2 O 4 and BaTiO 3 -CoFe 2 O 4 /polymer periodic composites are calculated using the plane-wave expansion method. The piezoelectric and piezomagnetic effects on the band structures are analyzed. The numerical results show that in CoFe 2 O 4 /quartz structures, only one narrow band gap exists along the C-X direction for the coupling of xy-mode and z-mode for the filling fraction f being 0.4; while in BaTiO 3 /CoFe 2 O 4 composites, only one narrow band gap exists along the C-X direction forxy-mode and no band gap exists for z-mode as the filling friction f is 0.5. Moreover, for the new type of magneto-electroelastic phononic crystal-BaTiO 3 -CoFe 2 O 4 /polymer periodic composite, the band gap characteristics are more superior in the whole considered frequency regions due to the big contrast of the material properties in the two constituents and the effects of the piezoelectricity and piezomagneticity on the band gap structures are remarkable.

Wave propagation and acoustic band gaps of two-dimensional liquid crystal/solid phononic crystals

“…For the sake of simplicity, we will only consider the elastic constant component related to longitudinal velocity. All the piezoelectric, electro-optical effects and medium viscosity will be neglected since piezoelectric phase mostly influences the z-mode [30].…”

Complete Band Gaps in Nano-Piezoelectric Phononic Crystals

“…PCs have many applications, such as vibration isolation technology [18][19][20][21][22] , acoustic barriers/filters [23][24][25] , noise suppression devices [26][27] , surface acoustic devices 28 , architectural design 29 , sound shields 30 , acoustic diodes 31 , elastic metamaterials [21][22]25,27,32 and thermal metamaterials [33][34][35][36][37][38][39] . There are also smart PCs that have been studied, such as piezoelectric [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] , piezomagnetic [55][56][57][58] and magnetoelectroelastic 14,[59][60][61]…”

Surface acoustic waves in acoustic superlattice lithium niobate coated with a waveguide layer

“…Until now, many researches related to the phononic crystals have been carried out, which involved the bulk waves in infinite structures, 4,5 Lamb waves in slabs 6,7 and surface waves in semi-infinite media. 8,9 For example, Wu et al obtained the dispersion relations of surface acoustic wave for phononic crystals consisting of circular cylinders of Bi 12 GeO 20 forming a square lattice in a SiO 2 matrix.…”