Electromechanical behavior of graphite intercalated with bromine

Graphite-bromine was found to produce a tensile stress (up to about 3 MPa) along the c-axis, upon heating by the passage of an electric current (with a current density of up to about 5 × 10⁵ A/m²) along the c-axis. This electromechanical effect was reversible and allowed electromechanical switching. The stress increase started at about 100°C upon heating. The c-axis electrical resistivity of graphitebromine was found to increase and then decrease upon heating and to increase and then decrease upon subsequent cooling, when the graphite-bromine sample was under mechanical constraint from expansion along the c-axis. These effects are attributed to the initiation of intercalate bubble formation as the sample was heated.