Propagation characteristics of SH waves in a functionally graded piezomagnetic layer on PMN-0.29PT single crystal substrate

• SH waves in a piezoelectric (PMN–0.29PT)/piezomagnetic layered media are studied.
• The behaviours of SH waves are dominated by the cut orientation of the PMN–0.29PT.
• Effect of the inhomogeneity of the piezomagnetic layer on the SH waves is shown.
• Effect of magnetic boundary conditions on the phase velocity is revealed.

The shear horizontal waves in a functionally graded piezomagnetic (FGPM) layer bonded on 0.71Pb(Mg1/3Nb2/3)O3–0.29PbTiO3 (PMN–0.29PT) single crystal substrate is investigated in this paper. The material parameters of the FGPM layer vary in the same exponential function along the thickness direction. The PMN–0.29PT single crystal under consideration is poled along the [011]c direction so that the macroscopic symmetry is orthonormal mm2. The dispersion equations are derived for the magnetically open and closed boundary conditions on the surface of FGPM layer. The dispersive behaviours are graphically illustrated and analyzed. The results show that the cut orientation of the PMN–0.29PT single crystal as well as the magnetic boundary conditions and gradient coefficient of FGMP layer have significant influences on the dispersion behaviours.