Intensity characterisation of polarisation vortex formation and evolution in ferroelectric nanofilms

Abstract

ABSTRACT As a class of typical topological structures, polarisation vortexes were characterised by the intensity vector which is defined as the curl of the polarisation at their cores. Some phase field simulations were conducted on the lead titanate nanofilms to evaluate the effects of model size, temperature, traction, and curled electric field on the formation and evolution of polarisation vortex intensity quantitatively. The results showed that increasing size, lowered temperature and increasing traction could enhance the polarisation vortex intensity, curled electric field could change the vortex rotation direction, and compressive or tensile traction could change the vortex shape. Therefore, the polarisation vortex could be tuned by the given conditions of model size, temperature, traction, and curled electric field. This is helpful to improve the understanding and control of polarisation vortex structure.