Magneto-volume effect in Fe n Ti13–n clusters during thermal expansion

Abstract

Ab initio molecular dynamics calculations have been carried out to search for the ground state structure of Fe n Ti13–n clusters and measure the thermal expansion of Fe n Ti13–n . The volume of Fe n Ti13–n clusters during thermal expansion is jointly determined by anharmonic interaction and magneto-volume effect. It has been found that Fe6Ti7, Fe9Ti4, Fe11Ti2, and Fe13 clusters can exhibit the remarkable magneto-volume effect with abnormal volume behaviors and magnetic moment behaviors during thermal expansion. A prerequisite for the magneto-volume effect of Fe n Ti13–n clusters during thermal expansion has been revealed and the magnitude of the magneto-volume is also approximately determined. Furthermore, the magneto-volume behaviors of Fe n Ti13–n clusters are qualitatively characterized by the energy contour map. Our results shed light on the mechanism of the magneto-volume effect in Fe n Ti13–n clusters during thermal expansion, which can guide the design of nanomaterials with zero expansion or even controllable expansion properties.