Browse Prior Art Database

DUAL GMR SENSOR DESIGN WITH IMPROVED STABILITY/BIASING

IP.com Disclosure Number: IPCOM000013094D
Original Publication Date: 2000-Apr-01
Included in the Prior Art Database: 2003-Jun-12

Publishing Venue

IBM

Abstract

The pinned ferromagnetic layers next to "Cu" spacer have pinned magnetizations coming out of the air bearing surface as shown in the figure. The net magnetizations of the pinned layers above and below the FREE layer are equal. This leads to cancellation of the pinned layer demagnetizing field acting on the FREE layer. The total thickness of the layers above the FREE layer is greater than the thicknesses of the layers below the FREE layer. This thickness difference provides net field from the sense current (Hi) acting on the FREE layer. For negative coupling between the FREE and pinned layers across the "Cu" spacer, the field from the sense current balances against the coupling field. Due to balance of the available fields, the FREE layer magnetization orientation parallel to the air bearing surface can be achieved leading to near zero asymmetry for the output signal. The cross-section of the sensor is shown below. The sense current flows out of the page. 1