Three-dimensional (3D) anisotropic functional properties are benefit to the multiple using of materials, and also contribute to their regulatory dimensionality. What general characteristics do 3D anisotropic functional materials have? How to explore materials with three-dimensional anisotropic functional properties in a variety of material systems? The 3D anisotropic structure of the material is the key point. It will provide structural assurance for anisotropy functional property.
In light of this, researchers from Institute of Solid State Physics, Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences (CAS) have successfully grown 3D layered MAB-phase MoAlB single crystal and discovered colossal 3D electrical anisotropy.
In this research, researchers used aluminum as a cosolvent and prepared high-quality and large-sized MoAlB single crystals. In this process, they found, unexpectedly, the huge 3D conductivity anisotropy in MoAlB single crystal, which was larger than previously reported.
In order to clarify its internal mechanism, they carried out experimental and theoretical studies. The 3D structural anisotropy of MoAlB was confirmed by single crystal X-ray diffraction (XRD) and transmission electron microscopy (TEM). 3D anisotropic electronic structure and chemical bond of MoAlB were confirmed by theoretical calculation.
3D anisotropic phonon vibration of MoAlB single crystal were observed in the measurement of Raman spectroscopy (RS). Therefore, the origin of this huge 3D anisotropic electrical conductivity was mainly attributed to its 3D anisotropy of crystal and electronic structure.
This study shed light on a new way to find 3D anisotropic functional material in layered material systems with 3D anisotropy of crystal structure and chemical bond.
Related work has been published on Small.
Fig. 1 3D anisotropic crystal structure of MoAlB single crystal（Image by HUANG Yanan）
Fig. 2 3D anisotropic phonon vibration of MoAlB single crystal（Image by HUANG Yanan）
Fig. 3 3D anisotropic electronic structure and electrical transport of MoAlB single crystal（Image by HUANG Yanan）