Nanosize confinement induced enhancement of spontaneous polarization in a ferroelectric nanowire

We theoretically showed that the spontaneous polarization in ferroelectric (FE) nanowires (NWs) can be considerably enhanced due to the nanosize confinement by the first-principles calculations. The spontaneous polarization along the wire direction in a fully relaxed PbTiO3 NW with 1.8 nm diameter is 1.26 times higher than that of bulk counterpart. The tension induced by NW surface curvature counteracts the near-surface depolarizing effect and meanwhile leads to the unusual enhancement of spontaneous polarization. These findings indicated that FE NWs can be promising in the applications of nanodevices. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3271175]