Future directions in electroplated materials for thin-film recording heads

Abstract

The need for recording heads to write on high-coercivity media at high frequencies has created new requirements for the write-head material that cannot be met by Ni <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">80</inf> Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</inf> , the nickel-iron alloy traditionally used in the fabrication of the device. Electroplating through a mask, the method of choice for depositing nickel-iron alloys, makes it possible to pattern and orient the magnetic film more readily than by other methods. We review here research performed mostly in the United States and in Japan to develop electroplated magnetic materials that can meet the new challenges of data storage technology. High-iron nickel-iron alloys (Ni <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">45</inf> Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">55</inf> ) have higher magnetic moment and resistivity than their low-iron counterparts and are increasingly being used in head fabrication. The addition of impurities in a controlled manner has been shown to produce drastic improvement in the properties of electroplated materials. And technology has been developed to fabricate laminated materials by electroplating from a single plating solution. Despite these advances in the electrodeposition of magnetic alloys, more research is required for electroplating processes to meet all of the challenges of data storage technology.