A magnetic head having a function element and the element made of a composite layer of magnetostrictive material and a piezoelectric material

摘要

PROBLEM TO BE SOLVED: To enable a minute displacement or minute contact pressure to be controlled without being affected by hysteresis or the change with time by laminating a piezoelectric material and a magnetostriction material, detecting a change in the former material with the latter, and feeding back to the control voltage of the piezoelectric material. SOLUTION: A PZT based piezoelectric ceramic 3, which is a piezoelectric body with an electrode 2 formed on both faces and polarized, is stuck to one face of an elastic substrate 1 composed of glass to form an actuator. On the top of it, an amolphous film 5, a magnetostriction film, is sputtered through an insulation film 4 of SiO2 to form a deformation sensor. With a voltage applied to the electrode 2 of the actuator, varying the applied voltage in positive and negative directions, the ceramic plate 3 bends vertically. Since the amolphous film 5 changes in magnetic permeability in accordance with the deflection of the elastic substrate 1, its deflection quantity is known by impressing a high frequency carrier at both ends of a Mianda pattern and detecting inductance.