Nanomagnets: Creating Order Out Of Chaos

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Nanomagnetic Devices – Use in New Kinds of Electronic Components

Nanomagnetic devices have been intended for use in new kinds of electronic components and scientists from Helmholtz-Zentrum Dresden-Rossendorf – HZDR have planned to use the ion beams for their fabrication. The beam, being ultra-fine comprising of around 10 neon ions serves in bringing several hundred atoms of an iron aluminium alloy into disarray thus generating a Nanomagnets inserted directly in the material. An unusual holographic technique is utilised on a transmission-electron microscope – TEM at the TU Dresden that portrays the magnetic field line and hence supports in measuring the precise dimension of the nanoscale magnets. Dr Rantej Bali, physicist, is especially interested in discovering new ways of miniaturizing magnets. He states that `one approach which is being adopted to this end is to use ion beams in generating Nanomagnets in certain materials’. One such material of choice is an alloy of iron and aluminium. It is paramagnetic in its ordered state which means that while the atoms tend to occupy specific places, the magnetic seconds on the electrons such as the spins, are focused at random and decoupled. On the other hand, ferromagnetic materials comprise of coupled spin and in principle electron spins could precisely adopt two states.

MRAM/Red Heads of Computer Hard Drives – Use Nanosized Ferromagnets

MRAM – Magnetoresistive random access memory or red heads of computer hard drives tend to use nanosized ferromagnets to read and store binary information. Spintronic applications are vigorously being researched all over the world for denser data storage and for energy efficient computing application. The latest way of producing spintronic element is by directly writing magnets on to alloy layers by utilising ions. Bali together with his team from the HZDR Institute of Ion Beam Physics and Materials Research have for the first time without the use of masks, fabricated these nanomagnets in a wafer thin layer of iron aluminium. He explained that with their highly focused ion beam, that is used like a magnetic stylus they could quickly generate prototypes of complex magnetic geometries. Another benefit was that the Nanomagnets were inserted in an electrically conductive layer that simplifies the development of spintronic components. The ion-generated magnets were successfully imaged by TU Dresden physicists, exposing their suitability for device applications.

One Ion – Generates a Nanomagnets in Iron Aluminium Alloy

Ideally, one ion would have the potential of generating a nanomagnet in the iron aluminium alloy. Bali explains that it is the same as in the case of a game of billiards wherein one single ball could set a cascade in motion. He further added that `they had calculated that one ion could displace up to 300 atoms’.Special ion microscope had been utilised in the latest experiments at the HZDR. The scientist responsible for the experiment, Dr Gregor Hlawacek, informed that six neon atoms were implanted in an area of one square nanometer. For the Nanomagnets, they had scanned the sample with a beam of two nanometers in diameter and generated a sequence of ferromagnetic stripes with narrow paramagnetic spacings. Such sequence of ferromagnetic and paramagnetic stripes, for spintronics is interesting. The Nanomagnets had been examined on the transmission electron microscope – TEM, where TU physicist Dr Falk Roder had mastered the art of TEM holography, in Triebenberg laboratory at the TU-Dresden. The team also wants to make joint use of the methods at the HZDR and at the TU Dresden in the near future for fabrication of nanomagnets in various forms.


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