GMR study leading to sensor fabrication on the Ag-Co system

The Ag-Co system either in multilayer or in granular alloy form exhibits th e Giant MagnetoResistance (GMR) effect. By adjusting the modulation paramet ers an intermediate structure may be formed offering new possibilities for magnetoelectronic applications. This structure resides in the Limit between multilayers and granular alloys and is called granular multilayer, This wo rk deals with the Ag-Co system and involves film growth by e-beam evaporati on, structural characterisation by X-ray and TEM facilities together with m agnetic (SQUID) and magnetotransport measurements. The dependence of GMR va lues on the individual layer thickness and on the total film thickness was parameterised and magnetoresistance values of 16% at 300 K and 36% at 30 K were achieved. The outcome of this study is the fabrication of a two-dimens ion magnetic field sensor consisting of eight specific elements forming a 2 x 4 array, The sensor is specialised in small magnetic held regions while its response was found quite satisfactory regarding its uniformity and repe atability, The sensor may be upgraded to larger arrays and to three dimensi ons in order to fulfil various market needs. (C) 2001 Elsevier Science B.V. All rights reserved.