A study of hard:soft layer ratios and angular switching in exchange coupled media

Abstract

We have performed micromagnetic simulations to investigate the magnetic behavior of exchange spring grains for hard disk recording applications. The thickness ratio between magnetically hard and soft layers was varied while the soft layer anisotropy was altered to maintain a suitable energy barrier between opposite magnetization states. The minimum required magnetic field for switching a grain and the corresponding field angle were both significantly reduced in exchange spring material compared with single-phase grains. This could lead to reduced cross-track write errors in hard drive systems and assist the development of magnetic multilayer recording technologies.

From compass to hard drive—integrated activities for studying magnets

“…In other words, this allows students to 'see into the mind of a computer'. There are many different aspects that can be discussed and explained, ranging from the basic concepts at junior level to tackling the latest engineering challenges at higher levels [5,6]. This is a whole-class class activity in which they are split into small groups to decipher part of the text and work together as a class to interpret the whole message.…”

Bringing science research into secondary schools

“…The outcome of this was to be able to optimize the hard : soft materials ratio to reduce the field required for switching and demonstrate that this will result in fewer write errors than for traditional single-phase hard drives. We have published the scientific results of this study elsewhere [5].…”