PMN-PT single crystal and Terfenol-D alloy magnetoelectric laminated composites for electromagnetic device applications

Abstract

Magnetoelectric laminated composites of a length-magnetized magnetostrictive Tb_0.3Dy_0.7Fe_1.92 (Terfenol-D) alloy plate sandwiched between two thickness-polarized, electro-parallel-connected piezoelectric 0.7Pb (Mg_1/3Nb_2/3)O₃-0.3PbTiO₃ (PMN-PT) single crystal plates were fabricated and their converse magnetoelectric properties were evaluated. An electromagnetic control device using a laminated composite as the control element and an Alnico biasing magnet, two Mn-Zn F-yokes and a Mu-metal movable plate as the magnetic circuit was developed and characterized. The distribution of the dc magnetic flux lines and magnetic inductions of the device were analyzed using a finite element method. The quasistatic and dynamic magnetic inductions of the device were measured, together with the generative forces. The results revealed that the device has linear voltage-controlled magnetic inductions in excess of 0.6 G/V with flat responses in the measured frequency range of 0.1-40 kHz and large generative forces over 0.7 N at 160 V at the designated gaps of 1.0-1.2 mm. This coil-free device could be useful in broadband and precision magnetic flux/force control applications with negligible Joule heating losses.