Crystals of the lead-free magnetic double perovskite. Photo: Thor Balkhed.
Crystals of the lead-free magnetic double perovskite. Photo: Thor Balkhed.

Scientists at Linköping University in Sweden have taken a step forwards in their work with the perovskite family of materials by developing an optoelectronic magnetic double perovskite. This discovery raises the possibility of coupling spintronics with optoelectronics for rapid and energy-efficient information storage.

Perovskites form a family of materials with many interesting properties: they are cheap to manufacture, have excellent light-emitting properties and can be tailored for different applications. Researchers have until now concentrated on developing variants for solar cells, light-emitting diodes and rapid optical communication.

Perovskites can consist of many different organic and inorganic substances, but they are defined by their special cubic crystal structure. One type of perovskite that contains halogens and lead has recently been shown to have interesting magnetic properties, opening the possibility of using it in spintronics.

In spintronics, information is stored in the direction of rotation of a particle (its spin), rather than its its charge (plus or minus). Spintronics is thought to have huge potential for the next generation of information technology, since it could allow information to be transmitted at higher speeds and with low energy consumption. But the magnetic properties of halide perovskites have so far only been demonstrated in lead-containing perovskites, which has limited the development of the material for both health and environmental reasons.

Together with colleagues in Sweden, the Czech Republic, Japan, Australia, China and the US, the scientists at Linköping University, led by Feng Gao, have now managed to create a lead-free perovskite alloy and produce a magnetic double perovskite.

In a paper in Science Advances, the scientists report incorporating magnetic iron ions, Fe3+, into a previously known double perovskite with interesting optoelectronic properties and consisting of caesium, silver, bismuth and bromine (Cs2AgBiBr6). They then showed in experiments that the new material displays a magnetic response at temperatures below 30K (-243.15°C).

"These are preliminary experiments from an exploratory investigation, and we are not completely sure of the origin of the magnetic response," says Gao. "Our results, however, suggest that it is probably due to a weak ferromagnetic or anti-ferromagnetic response. If so, we have a whole class of new materials for future information technology. But more research is needed, not least to obtain the magnetic properties at higher temperatures.

"Perovskites are exciting materials, and they have a huge potential for use in future products that need the cheap and rapid transfer of information."

This story is adapted from material from Linköping University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.