Capturing the 2D and 3D electronic states of novel and exotic materials
Capturing the 2D and 3D electronic states of novel and exotic materials lead image
Novel materials may demonstrate unexpected properties that can lead to new applications for devices, but current methods for analyzing their electronic structures at sub-micrometer levels use intensely focused light that damages the sample.
Matsui et al. developed a new instrument, the Photoelectron Momentum Microscope or PMM, which can visualize electronic states within a microscopic region of a novel material without harming the sample. The PMM applies micrometer-scale photoelectron spectroscopy to analyze the electronic states of several materials.
With their new instrument, the team visualized the “Fermi surface” of iridium thin films, the 3D Fermi surface of a gold crystal, and the changing electronic states of a novel chalcogenide 2D material with temperature. Since the Fermi surface defines the allowable energies of electrons in a solid, understanding the Fermi surface is essential to helping scientists understand the electronic properties of a material.
“PMM is an instrument built on a new concept based on imaging-type photoelectron spectroscopy and microscopy techniques to visualize the electronic state in reciprocal space of a selected microscopic region,” author Fumihiko Matsui said. “A key feature of the PMM is that it can very effectively reduce radiation-induced damage by directly projecting a single photoelectron constant energy contour in reciprocal space with a radius of a few reciprocal Angstroms inverse or real space with a radius of a few hundred micrometers onto a 2D detector.”
The team plans to improve their instrument by creating a 2D spin filter, which may enable the team to visualize the 2D spin “texture” or surface of novel materials and lead to other electronic applications.
Source: “Soft X-ray photoelectron momentum microscope for multimodal valence band stereography,” by Fumihiko Matsui, Kenta Hagiwara, Eiken Nakamura, Takayuki Yano, Hiroyuki Matsuda, Yasuaki Okano, Satoshi Kera, Eri Hashimoto, Shinji Koh, Keiji Ueno, Takahiro Kobayashi, Emi Iwamoto, Kazuyuki Sakamoto, Shin-ichiro Tanaka, and Shigemasa Suga, Review of Scientific Instruments (2023). The article can be accessed at https://doi.org/10.1063/5.0154156 .
