Search

This study presents a magnetostrictive type inductive sensing pressure sensor which consisted of a planar coil, CoFeB magnetic films, and a Si diaphragm. As the Si diaphragm deformed by a pressure load, the inverse-magnetostriction effect would cause permeability changes of the CoFeB magnetic films. Thus, the permeability changes as well as the pressure load can be detected by the inductance change of a planar inductor. To demonstrate the feasibility of the proposed pressure sensor, the planar inductor designs of different coil turns and in-plane patterns of magnetic films are fabricated and tested. Preliminary measurements show that the pressure sensors with 6 and 12 coil turns have sensitivities of 0.079 %/kPa and 0.064 %/kPa, respectively. In addition, based on the in-plane pattern design of the magnetic films, the gauge factor could be tuned from 55 to 852. [ABSTRACT FROM AUTHOR]

We grow perpendicular L10-FePt films epitaxially on (001)[Pb(Mg1/3Nb2/3)]0.7-(PbTiO3)0.3 ferroelectric substrates. Due to the magnetostriction effect, the out-of-plane coercivity (Hc⊥) of the L10-FePt varies with applied electric fields, showing an asymmetric butterfly-like loop. The Hc⊥ at the zero-electric-field state (Hc⊥,0) shows a nonvolatile change, depending on the direction of the poling electric field. The magnitude of nonvolatile magnetic anisotropy change, induced by the ferroelectric field effect, can be comparable to the anisotropy change induced by pure electric fields. The nonvolatile magnetic anisotropy change is inversely proportional to the FePt thickness and can be eliminated by inserting a metallic intermediate layer. [ABSTRACT FROM AUTHOR]