Interface Stability-Controlled Growth of FexGe on Ge (100), (110), and (111) Substrates

Interface Stability-Controlled Growth of FexGe on Ge (100), (110), and (111) Substrates

The Journal of Physical Chemistry C

10.1021/acs.jpcc.2c00392

http://dx.doi.org/10.1021/acs.jpcc.2c00392

Wen-Ya Wu, Junfeng Gao, Siew Lang Teo, Weng Weei Tjiu, Shi Feng Guo, DongZhi Chi, Qiang Zhu, Ming Lin

FeGe/Ge, interface stability, hexagonal, monoclinic, epitaxial, endotaxial

26 April 2022

Wu, W.-Y., Gao, J., Teo, S. L., Tjiu, W. W., Guo, S. F., Chi, D., Zhu, Q., & Lin, M. (2022). Interface Stability-Controlled Growth of FexGe on Ge (100), (110), and (111) Substrates. The Journal of Physical Chemistry C, 126(17), 7674–7679. https://doi.org/10.1021/acs.jpcc.2c00392

The electronic and magnetic properties of materials are strongly influenced by their surface and interface structures and configurations. In this work, we have grown FexGe single crystalline islands on the Ge substrate with three different surfaces, (001) (110), and (111), and investigated the interface structures between FexGe crystals and Ge substrates. The FexGe crystals result in two distinct phases on all three Ge substrates, namely, monoclinic and hexagonal. Using TEM/HRTEM, 3D rotational electron diffraction, and DFT simulation approaches, we carefully studied the facet orientation at the interface and explained the coexistence and formation mechanism of the monoclinic-FeGe and hexagonal-Fe13Ge8. Although Ge substrates with different orientations were used in the study, our findings suggest a unique facet preference that all the FexGe crystals tend to grow with Ge {111} epitaxially or endotaxially. Combining simulation of energy difference on selected facets, lattice mismatch, and the dangling bond density, we derive the mechanism of such a phenomenon as an interfacial equilibrium driven by the difference of interface energy. Our study provides valuable information in the FexGe/Ge system and will potentially benefit the future development of FexGe-related electronic/ magnetic devices.

Publisher Copyright

This research / project is supported by the A*STAR - Investigating Spin Topology (Skyrmions)
Grant Reference no. : IMRE/15-2C0410

Acknowledges the support from the National Natural Science Foundation of China (No. 12074053) and XinLiaoYingCai Project of Liaoning province, China (XLYC1907163). Shifeng Guo thanks the support from the National Natural Science Foundation of China (Grant No.52071332) and the Science and Technology Innovation Commission of Shenzhen (Grant No. JCYJ 20180507182239617)

This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see doi.org/10.1021/acs.jpcc.2c00392

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