A recent study conducted by the Institute of Metal Research (IMR) of the Chinese Academy of Sciences (CAS) and collaborators from the Institute of Physics of CAS has led to the direct observation of polar Bloch points in strained ferroelectric films. This groundbreaking discovery has been published in Nature Communications.
Bloch points are singular points around which field vectors are oriented in nearly all directions, and they serve as a natural link between classical and quantum magnetism in magnetics. Until now, polar Bloch points had only been predicted in a few cases in ferroelectrics and had not been directly observed until this study.
The researchers from IMR and CAS considered a model of a tensile-strained ultrathin ferroelectric PbTiO3 film sandwiched by symmetric electrodes in phase-field simulations. Through this approach, they discovered that merons transform into Bloch points as the electrode thickness increases.
In their experimental setup, a trilayer SrRuO3/PbTiO3/SrRuO3 film was grown on a SmScO3 substrate using pulsed laser deposition. Aberration-corrected scanning transmission electron microscopic imaging was then employed to observe the polarization configuration of polar Bloch points within the film. Phase-field simulations conducted by the researchers further predicted the existence of a region of negative capacitance around each polar Bloch point.
The implications of this discovery are significant as it expands the assembly of topological ferroelectric domain structures and suggests novel applications in future integrated circuits and low-power electronic devices. This research sheds new light on the nature of ferroelectric materials and provides valuable insights for the development of advanced technologies in the field.
In summary, recent research by IMR and CAS has led to the direct observation of polar Bloch points in strained ferroelectric films, providing valuable insights into topological ferroelectric domain structures and suggesting potential applications in future integrated circuits and low-power electronic devices.
