arXiv subjects

Mohammed H. Yusuf

Publications and source records attributed to Mohammed H. Yusuf.

2 recordsLinked to original sources

arXiv2019

Role of temperature-dependent electron trapping dynamics in the optically driven nanodomain transformation in a PbTiO${_3}$/SrTiO${_3}$ superlattice

The spontaneously formed striped polarization nanodomain configuration of a PbTiO${_3}$/SrTiO${_3}$ superlattice transforms to a uniform polarization state under above-bandgap illumination with a time dependence varying with the intensity of optical illumination and a well-defined threshold intensity. Recovery after the end of illumination occurs over a temperature-dependent period of tens of seconds at room temperature and shorter times at elevated temperatures. A model in which the screening of the depolarization field depends on the population of trapped electrons correctly predicts the observed temperature and optical intensity dependence.

cond-mat.mtrl-sci↗

arXiv2017

Photoinduced Domain Pattern Transformation in Ferroelectric/Dielectric Superlattices

The nanodomain pattern in ferroelectric/dielectric superlattices transforms to a uniform polarization state under above-bandgap optical excitation. X-ray scattering reveals a disappearance of domain diffuse scattering and an expansion of the lattice. The reappearance of the domain pattern occurs over a period of seconds at room temperature, suggesting a transformation mechanism in which charge carriers in long-lived trap states screen the depolarization field. A Landau-Ginzburg-Devonshire model predicts changes in lattice parameter and a critical carrier concentration for the transformation.

cond-mat.mtrl-sci↗