AFM-based functional tomography - to mill or not to mill, that is the question!
Abstract:
The electrical response of ferroelectric domain walls is often influenced by their geometry underneath the sample surface. Tomographic imaging in these material systems has therefore become increasingly important for its ability to correlate the surface-level functional response with subsurface domain microstructure. In this context, AFM-based tomography emerges as a compelling choice because of its simplicity, high resolution, and robust contrast mechanism. However, to date, the technique has been implemented in a limited number of ferroelectric materials, typically to depths of a few hundred nanometers or on relatively soft materials, resulting in an unclear understanding of its capabilities and limitations. In this work, AFM tomography is carried out in YbMnO3, mapping its complex domain microstructure up to a depth of ≈1.8 µm along with its current pathways. A model is presented, describing the impact of interconnected domain walls within the network, which act as current dividers and codetermine how currents distribute. Finally, challenges such as tip-blunting and subsurface damage are identified through TEM studies, and strategies to address them are also put forward. This study highlights the potential of AFM tomography and can spur interest within the ferroics community for its use in the investigation of similar material systems.
AFM‐Based Functional Tomography – To Mill or Not to Mill, that is the Question!
Elastic softness of low-symmetry frustrated ATi2O5 (A=Co,Fe)
An in-depth analysis of the structure, optics, morphology and photocatalytic characteristics of cerium doped tin oxide nanoparticles
Switching of ferrotoroidal domains via an intermediate mixed state in the multiferroic Y-type hexaferrite Ba0.5Sr1.5Mg2Fe12O22
Abstract:
We report a detailed study of the magnetic field switching of ferrotoroidal/multiferroic domains in the Y-type hexaferrite compound Ba0.5Sr1.5Mg2Fe12O22. By combining data from superconducting quantum interference device (SQUID) magnetometry, magnetocurrent measurements, and resonant x-ray scattering experiments, we arrive at a complete description of the deterministic switching, which involves the formation of a temperaturedependent mixed state in low magnetic fields. This mechanism is likely to be shared by other members of the hexaferrite family, and presents a challenge for the development of high-speed read-write memory devices based on these materials.