By ‘shining’ a beam of electrons on a special ceramic material, a University of Sydney team has found a new way for increasing the memory capacity of computer hard drives.
Responding to consumer demand for increased computer hard drive memory, this work also has the potential to reduce the environmental footprint of the more than 2.5 billion hard drives currently estimated to be in use worldwide.
Results of the material science and engineering research have been published in the American Physical Society’s journal Physical Review Letters.
Lead author Zibin Chen, a PhD candidate at the University’s Faculty of Engineering and Information Technologies says: “If you lined up all the world’s hard drives back-to-back, they would go around the globe five times, and hard drives are partly manufactured from non-biodegradable aluminium and other metals.
“Finding a way to increase memory capability without increasing the hard drive size is a major challenge in this area.
“The project focussed on the materials science for memory storage. In some oxide ceramics called ferroelectric materials, there exist tiny domains that can that contain an electric dipole that is switchable. Two opposite dipole directions can be used as the two logic signals ‘0’ and ‘1’, so that they can serve as memory bits.
“The key challenge is how to ‘set’ the domains to one condition or the other, and how to ‘switch’ the domains once written. Conventional techniques use local heating, mechanical stress or electrical bias—all of which have major drawbacks.
“We have discovered that a high-energy electron beam with an omni-directional electric field does the job!
“We are proposing an approach that could reduce the current domain size by 100 times, resulting in a 100 times greater data storage capability.
“This new materials science creates a roadmap that can be used by industry to create a next generation of better, greener, more stable computer memory,” says Zibin.
The PhD research was co-supervised by Professors Xiaozhou Liao and Simon Ringer from the Faculty of Engineering and Information Technologies, whose work is part of the Faculty’s Materials and Structures Research Group.
Professor Xiaozhou Liao says: “The most notorious cause of failure for computer hard drives is a head crash, where the ‘head’ of the device that hovers just above the rotating disk touches or scratches the data-storage platter surface. A head crash usually incurs severe data loss.
“Our approach requires no physical contact of a tip or any other manipulator with the data storage media and therefore avoids possible physical damage to the devices.
Professor Ringer explains: “As materials engineers, we think a lot about how to stimulate local changes in the atomic-scale structure of materials so as to access remarkable new properties and behaviour.
“We are really excited to have discovered that applying these local electric fields with nanoscale precision can create a new paradigm for computer memory.”
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