Bodily floor particulars of mica studied on an atomic scale

At first look, mica is one thing fairly unusual: it’s a widespread mineral, present in granite for instance, and has been extensively studied from geological, chemical and technical views.

One would possibly suppose that nothing new might be found from such an on a regular basis materials. However now a group from the Vienna College of Expertise has offered a examine within the journal Nature Communications, explaining the distribution of potassium ions on the mica floor. The bodily floor particulars of mica have by no means been studied on an atomic scale, and this data is necessary for analysis on electronics with 2D supplies.

Atomically skinny layers

Atomically skinny–layered 2D supplies are at the moment one of the crucial researched subjects in supplies science. Sure supplies, comparable to graphene and molybdenum disulfide, encompass just one or a number of layers of atoms, which often results in uncommon properties.

In a way, mica is a naturally occurring 2D materials: It consists of atomically skinny layers that may comprise totally different atoms relying on the kind of mica: oxygen is at all times current, typically silicon, typically potassium or aluminum as effectively. The layer construction of the mica can also be the rationale for its attribute sheen—you’ll be able to typically see a spectrum of colours, much like a skinny layer of oil on a puddle of water.

Potassium ions in extremely excessive vacuum

The outermost layer of mica is tough to look at as a result of it’s shortly contaminated by atoms and molecules from the air. The researchers imaged the floor of mica in an ultra-high vacuum, utilizing a brand new kind of atomic pressure microscope on the Vienna College of Expertise.

“We had been capable of see how the potassium ions are distributed on the floor,” says Giada Franceschi, the primary creator of the present paper, who works in Prof. Ulrike Diebold’s group. “We had been additionally capable of acquire insights into the positions of the aluminum ions underneath the floor layer—this can be a notably tough activity experimentally.”

The pictures present that the potassium ions should not randomly distributed on the floor, as beforehand assumed, however are organized in tiny patterns. These distributions may be calculated with the assistance of pc simulations.

Matching insulator for 2D electronics

This work may very well be necessary for, amongst different issues, makes an attempt to make use of 2D supplies comparable to graphene for digital circuits. Appropriate insulators are wanted for this, and mica is a really apparent candidate.

“The floor properties of mica will play an important position in such digital elements,” says Giada Franceschi.