# Synopsis: Data Mining for a Graphene Cousin

Researchers have searched a crystallographic database to uncover 92 solids that should be easy to exfoliate into two-dimensional sheets with potentially useful electronic properties.

Graphite was used for years in lubricants, pencils, and batteries before researchers tried to separate it into graphene, a one-atom-thick layer of carbon atoms with enormous potential in electronics. In hindsight, could there be other solids like graphite that have simply been missed? To help identify them, Sébastien Lebègue, of the French National Center for Scientific Research (CNRS) in Nancy, and his colleagues have mined a vast database of crystal structures and pinpointed $92$ they believe can be easily exfoliated into atomically-thin layers. As reported in Physical Review X, several of these materials could have technological applications.

Graphite peels easily because its atoms are strongly bonded in one plane but weakly bonded between these planes. Lebègue et al. identified common geometrical traits of such materials, including a large separation between planes of atoms and an atomic packing density that is neither too high (as in metals) nor too low (as in molecular solids). They used these traits to design a search algorithm that sifted through thousands of solids in the Inorganic Crystal Structure Database, looking for a match.

The search turned up familiar materials including graphite (thankfully), its structural cousin hexagonal boron nitride, and a family of materials called the transition-metal dichalcogenides. The real potential lies in those $40$ tagged compounds with strongly bonded 2D sheets whose properties haven’t yet been studied in depth. According to the authors’ calculations, several of these materials have 2D layers that are semiconducting with a moderately sized band gap, a property essential for making transistors and one that even graphite lacks. – Jessica Thomas

Correction (9 July 2013): The Synopsis incorrectly stated that the materials FeSe and LiFeAs were dichalcogenides. This has been corrected.

More Features »

### Announcements

More Announcements »

## Subject Areas

Materials Science

Astrophysics

Astrophysics

## Related Articles

Materials Science

### Synopsis: Golden Mystery Solved

A long-standing discrepancy between experiments and theory concerning the electronic properties of gold has now been resolved. Read More »

Materials Science

### Synopsis: Metamaterial Inverts the Hall Effect

A metamaterial that looks like chainmail has a Hall coefficient whose sign is flipped compared to the material it’s made from. Read More »

Mechanics

### Focus: Why Some Gels Shrink under Stress

The gel material that helps blood clot in a wound has anomalous material properties because of the interaction between the gel's fluid and its microscopic fiber network, according to experiments. Read More »