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Methods for Domain Optimization in Recording Heads

IP.com Disclosure Number: IPCOM000015626D
Original Publication Date: 2002-Jul-20
Included in the Prior Art Database: 2003-Jun-20

Publishing Venue

IBM

Abstract

Disclosed is a method for locally influencing the effective magnetic anisotropy in patterned magnetic devices leading to improved performance of inductive and magneto-resistive recording heads and related magnetic devices. The technique is based on locally changing the magnetic properties of patterned magnetic devices by locally adjusting the effective material composition, the physical structure, the mechanical stress distribution, or a combination of the methods mentioned above. The domain structure, or better, the effective magnetic anisotropy, in recording heads strongly influences the magnetic performance of heads used for data storage applications. For example domain instabilities in the magnetic shields adjacent to the magneto-resistive (MR) sensor contribute to degraded performance due to induced noise in the read back signal. Another application of the enclosed methods is the optimization of the domain structure in magnetic yokes for high-speed writing applications. The patterned thick magnetic films, used for magnetic shields and flux delivering parts in magnetic recording heads are strongly sensitive to stress relaxation at the edges and the air-bearing surface (ABS). The existing stress anisotropy can be of the order of several 100MPa and leads together with even small values of magnetostriction to large changes in magnetic anisotropy. A typical stress distribution in a patterned magnetic film used in recording heads together with the resulting stress anisotropy over one edge is shown in Fig.1. 0 20 40 6080100