Ferrorotational domain walls revealed by electric quadrupole second harmonic generation microscopy

Ferrorotational Selectivity in Ilmenites

“…Compared with other techniques currently used for visualizing FR domains, our selective polishing method shows considerable advantages in terms of scalability and practicability. The linear electrogyration effect, XRD diffraction, TEM, and scanning EQ SHG microscopy have been utilized to observe the FR domains. ,− Both linear electrogyration imaging and XRD diffraction require transparent thin sample plates with minimal impurities, which can only be obtained via extensive polishing for single crystals grown by the floating zone method. Furthermore, transparent electrodes must be additionally sputtered on the polished surfaces to allow the application of a voltage in linear electrogyration imaging.…”

“…More recently, scanning EQ SHG microscopy has been employed to visualize FR domains and resolve the FR domain walls. 15 Note that all of these methods mentioned above require delicate sample preparation in tandem with complicated data collection. A simple method to achieve the ferrorotational selectivity of FR domains with the desired conjugate axial-vector field will impact and likely facilitate further understanding of the FR order and realization of its new functionalities.…”

“…Later on, the X-ray diffraction (XRD) diffraction mapping method was also developed to observe FR domains. More recently, scanning EQ SHG microscopy has been employed to visualize FR domains and resolve the FR domain walls . Note that all of these methods mentioned above require delicate sample preparation in tandem with complicated data collection.…”