15-Mode piezoelectric composite and its application in a magnetoelectric laminate structure

Highlights: • Piezoelectric ceramic-epoxy composite material is newly proposed and fabricated. • The composite material exhibits excellent 15-mode piezoelectric properties. • Magnetoelectrics with the composites show a structural bending characteristic. • The bending resonance enables a giant magnetoelectric effect at low frequencies. Magnetoelectric composites have recently been attracting attention owing to their possible application in various advanced electronics. The piezoelectric material used in a magnetoelectric composite is an important determinant of the electrical performance of the device. In this study, we report on the fundamental characteristics and magnetoelectric application of a 15-mode piezoelectric composite. The centimeter-scale 15-mode piezoelectric composite implemented by a novel fabrication process exhibits successful 15-mode operation along with excellent piezoelectric properties d₁₅ = 793 × 10⁻¹² C N⁻¹, g₁₅ = 32 × 10⁻³ V m N⁻¹, k₁₅ = 0.62, and d₁₅·g₁₅ = 25376 × 10⁻¹⁵ m² N⁻¹. Magnetostrictive-piezoelectric laminate structures designed to generate shear stress were fabricated using the 15-mode piezoelectric composites, and their magnetoelectric characteristics were investigated systematically. A giant magnetoelectric voltage coefficient of 18.4 V cm⁻¹ Oe⁻¹ was obtained at a low frequency of 660 Hz from the laminate, indicating the potential of the 15-mode piezoelectric composite for application in high-performance magnetoelectric devices.