Material with no name

Scientists at the University of California, Riverside have created a new bistable material that is likely to interest the electronics and computer storage industry.

Scientists at the Centre for Nanoscale Science and Engineering at the University of California, Riverside have reported a new bistable material that is likely to interest the electronics and computer storage industry.

The material, as yet without a popular name, is said to simultaneously exhibit bistability in three properties (or physical channels): optical, electrical, and magnetic.

‘We fabricated the material thinking it should have novel conductivity properties,’ said Robert Haddon, professor of organic materials chemistry and engineering at UCR. ‘But when we measured the properties we discovered the bistability.’

A bistable material is one that can exist in either one of two different states. The ability of a material to switch between two states is the basic requirement for a device such as a transistor.

When two different physical channels of a material are simultaneously involved in the switching, new applications and new fields of research can emerge.

‘When our material switches between states,’ said Haddon, ‘it switches the conductivity, the amount of light transmitted, and the magnetism. Engineers are always trying to develop materials that switch between two states in such a way that the switching is manifested in more than one physical channel.’

Haddon explained that in a transistor, switching occurs between two states in which the conductivity is different. In a computer storage device, switching occurs between two states, which have different magnetic properties. Photonic devices switch the amount of light allowed to pass through a material.

‘Ultimately, to develop very sophisticated devices and new technologies,’ he said, ‘we need materials that combine one or two of three channels: optical, electrical and magnetic channels. Our material, as far as we know, is the first organic compound that combines all three.’

Haddon mentioned that his team’s multifunctional material has the potential to be used as the basis for new types of electronic devices, where multiple physical channels are utilised for writing, reading, and transferring information.

The new material, which the UCR team calls a ‘neutral radical organic conductor,’ reportedly exhibits bistability just above room temperature.

One state, they note, is paramagnetic (attracted to a magnetic field), insulating, and infrared transparent. These properties reverse in the other state, producing a material that is diamagnetic (repelled by both poles of a magnet), conducting, and infrared opaque.