New layer-by-layer constructed inorganic-organic materials permits optical switching of magnetic properties

Materials chemists have developed a facile course of for piling ultrathin inorganic and natural layers in a pre-designed method into versatile room-temperature thin-film magnets, whose magnetic properties might be managed with successive exterior gentle illuminations.

In the massive information period, photo-controlled room-temperature magnets might open new horizons for high-density info storage, specifically, if these supplies might be synthesized from non-critical uncooked supplies and fabricated in device-integrable thin-film type. Now a staff of Aalto University researchers from the Department of Chemistry and Material Science and the Department of Applied Physics report such dream-of-the-dream supplies.

For the fabric fabrication, the Aalto researchers make the most of the Millennium Prize awarded ALD (atomic layer deposition) expertise, which they’ve modified in order that throughout the ALD-grown ferrimagnetic inorganic layers ultrathin photo-switchable natural layers might be deposited by means of extra MLD (molecular layer deposition) cycles.

The inorganic element harnessed by the researchers into these skinny films is exclusive itself, because it possesses a particularly excessive magnetic coercivity subject, however is on the similar time actually easy in its chemical composition, being composed of iron and oxygen solely.

The staff demonstrated for his or her ɛ-Fe₂O₃:azobenzene superlattice skinny movies the reversible transformation from the straight trans-azobenzene type into the bent cis-azobenzene type, and again, when the movies have been shone alternatively with UV and visual gentle. Most importantly, this structural change between the elongated and squeezed azobenzene kinds was proven to behave as a sort of optical switcher for the magnetic properties of the ɛ-Fe₂O₃ layers.

The mechanical flexibility provided by the embedded azobenzene layers is a further bonus for these movies, making them extremely engaging materials parts for the next-generation versatile electronics.

“This is a big step forward, as these new optically controlled thin film magnets with inbuilt flexibility can outperform both the classic rigid inorganic magnets composed of heavy and rare raw materials and the recently highlighted molecular magnets which are fundamentally weaker in their magnetic performance,” says Dr. Anish Philip from Aalto University, School of Chemical Engineering.

“The currently strongly emerging ALD/MLD technique provides us with an elegant way to build these advanced functional materials with atomic-level control,” emphasizes Professor Maarit Karppinen. “This is a new direction for the conventional ALD thin-film technology, and our research group at Aalto is one of the forerunners in this field.”

The examine was lately revealed within the Journal of Materials Chemistry C.