Greener nanomagnets

The work by a team of geomicrobiologists from Manchester University paves the way for nanometer-size magnets – used in mobile phones and recording devices – to be made without certain chemicals and energy-intensive methods.

Researchers studied iron-reducing bacteria that occur naturally in soils and sediments and found they can be used to create iron-oxide nanoparticles with magnetic properties similar to those created through complex chemical processes.

Working with colleagues in Birmingham and Cardiff, the Manchester researchers also found a way of exercising precise control over the size and magnetic strength of nanomagnets produced.

Particle accelerators at the Advanced Light Source at Berkeley Labs near San Francisco, and the UK’s Diamond Light Source in Oxford at Harwell were used to verify findings.

Researchers added cobalt, manganese or nickel to the basic iron-based energy source used by bacteria, which resulted in the production of tiny magnets containing these elements. This is said to have greatly enhanced their useful magnetic properties.