Spinning New Solutions with Magnetism

 

16 April 2014

The word ‘magnet’ may well conjure up an image of a horseshoe-shaped bar picking up paper clips, but co-ordination chemist Dr Grace Morgan has her eye on something considerably smaller. She is looking to harness the atoms of metallic elements, where the spin of the electrons determines their magnetic properties. And by cleverly engineering transition metals, she is opening up new possibilities - including how to store information more effectively on electronic devices.

“At its heart any electronic device is an assembly of chemicals, that, through state changes, process and store information,” explains Dr Morgan, who is a Senior Lecturer at UCD School of Chemistry. “There is always a demand for increased processing speeds and for higher storage capacity, and industry is now looking to get down to the molecular level to do that.”

Dr Morgan’s approach uses transition metal molecules that can exist in two states, both of which are stable under the same conditions: by switching the spin of their electrons, you could effectively process or store new patterns of information in the chemical arrays, she explains.

“We work with a set of transition metal complexes where you can store information inside the molecule - by changing the temperature we can switch between a high-spin and low-spin arrangement and this lets you manage the information in your device.”

At the moment Dr Morgan uses the metal manganese for the spin switching and published a paper in 2012 about its spin transition in the prestigious journal Angewandte Chemie. Her lab is now designing a chemical framework around the metal. “It is like a little tap so you can turn on spin,” she says. “And if you can decorate the ligand around the metal, you can make it into a nano-object which in turn makes it easier to engineer.”

Dr Morgan is also looking to engineer ‘soft media’ switches using ionic liquids, where magnets could be used to ‘write’ the information into the chemistry. “We can put the switches on a nano-fluidic surface and manipulate them with magnetic fields,” she explains. “Different droplets will have different spin states, so they will respond differently. But this is quite difficult to achieve.”

As these transition metals flip between spin states, they absorb heat, but they don’t become hot - a phenomenon known as phase transition - and Dr Morgan is working with industry to explore how they could help to control heat in devices.

“The challenges now are to engineer these materials so that operate over many years without degradation and that they will work across a range of temperatures, whether they are in Alaska or Australia.”

Her lab is also exploring how to engineer transition metals so they can ‘pull’ carbon from the atmosphere, and thus provide material for making fine chemicals. “It’s a free source of carbon and it’s the final sink for fossil fuels that are burnt: if you recover that and make fine chemicals, that would be very useful for indigenous industry.”

Dr Grace Morgan, Senior Lecturer with UCD School of Chemistry, was interviewed by freelance journalist Dr Claire O'Connell.