Can copper be turned into gold? For centuries, alchemists pursued this dream, unaware that such a transformation requires a nuclear reaction. In contrast, graphiteβthe material found in pencil tipsβand diamond are both composed entirely of carbon atoms; the key difference lies in how these atoms are arranged.
Converting graphite into diamond requires extreme temperatures and pressures to break and reform chemical bonds, making the process impractical. A more feasible transformation, according to Prof. Moshe Ben Shalom, head of the Quantum Layered Matter Group at Tel Aviv University, involves reconfiguring the atomic layers of graphite by shifting them against relatively weak van der Waals forces.
This study, led by Prof. Each layer behaves like a LEGO brickβbreaking a single brick is difficult, but separating and reconnecting two bricks is relatively simple. Similarly, in layered materials, the layers prefer specific stacking positions where atoms align perfectly with those in the neighboring layer. By applying an electric field or mechanical pressure, we can shift the layers into various stable configurations. Their team has also explored how different numbers of layers influence material properties.
For example, three layers of a material with two types of atoms can create six distinct stable materials, each with unique internal polarizations.
With five layers, this number increases to 45 different possible structures. By switching between these configurations, researchers can control electrical, magnetic, and optical properties. Even graphite, composed solely of carbon, can rearrange into six different crystalline forms, each with distinct electrical conductivities, infrared responses, magnetizations, and superconducting properties. With continued research, these sliding materials could revolutionize technology, offering faster, more efficient memory storage and unprecedented control over material properties.
