Sam Ladak is a lecturer in the School of Physics and Astronomy at Cardiff University. In this article he discusses his work into tiny 3D magnets that may be used for next generation data storage.
Magnetism is a fascinating force of nature and is responsible for phenomena observed over many different length scales. For example, magnetism plays an important role in the production of solar flares, the huge violent eruptions of matter seen upon the surface of the sun. On the opposite end of the scale, the arrangement of permanent magnets, that are 1000 times smaller than the width of a human hair, allow us to store vast amounts of data such as photos, MP3s and video.
Most personal computers and laptops store data using a device called a computer hard disk drive. These devices consist of a round platter upon which there are millions of tiny bar magnets laying face down. The direction in which the North Pole faces in these magnets dictates the information they store. If the North Pole points in one direction, it stores a digital ‘0’ and if it stores in the opposite direction it stores a digital ‘1’. Intensive research into these tiny magnets, both within universities and industry, has led to hard disk drive magnets getting smaller. The smaller the magnets are, the more of them you can squeeze onto the platter and this has resulted in a greater storage capacity.
One of the fundamental challenges that society faces is new ways to store very large amounts of information. Fundamental physical principles will limit the further reduction of hard disk drive magnets within ten years and this will limit further increases in storage capacity. In contrast, the amount of data that the average person stores is increasing exponentially. One way to dramatically increase the amount of data stored within a magnetic device is to exploit the third dimension. The creation of tiny magnets that have 3D geometries, and can be stacked, has the potential to revolutionise information storage. In order to create such devices we first need to learn about the fundamental physics that governs simple 3D nanomagnets.
My research utilises a very novel fabrication method that uses a laser to carve out tiny 3D magnets. The process, which is not dissimilar to 3D printing, allows the creation of any 3D geometry allowing the exploration of a vast parameter space. Once fabricated we use instruments within my laboratory and at other institutions around the world to image the magnetism within the 3D structures and understand their properties.
Another aspect of my research is embedding these tiny 3D magnets within other materials that have specific properties. The result is a novel composite material that has a unique set of electrical and magnetic properties. These materials can be used to build devices that require very little energy to function and have the potential to revolutionise a number of technologies. For example, next generation mobile phones that use these materials within electrical circuits will consume less energy and thus have a longer battery life.
Further research into tiny 3D magnets by myself and others will allow the creation of novel devices that can store vast amounts of information, whilst using little energy. Such devices may be found within your computer, mobile phone or mp3 player within 20 years.
Sam may be contacted at LadakS@cardiff.ac.uk
This article first appeared in the Western Mail on 1st December 2014, as part of the Welsh Crucible series of research profiles.