The control of chemical exchange across heterointerfaces formed between ultra-thin functional transition-metal oxide layers provides an effective route to manipulate the electronic properties of these systems. We show that cationic exchange across the interface between the Mott insulator, LaTiO3(LTO) grown epitaxially on SrTiO3(STO)-buffered Silicon by molecular beam epitaxy depends strongly on the surface termination of the strained STO buffer. Using a combination of temperature-dependent transport and synchrotron X-ray crystal truncation rods and reciprocal space mapping, an enhanced conductivity in STO/LTO/SrO- terminated STO buffers compared to heterostructures with TiO2-terminated STO buffers is correlated with La/Sr exchange and the formation of metallic La1−xSrxTiO3. La/Sr exchange effectively reduces the strain energy of the system due to the large lattice mismatch between the nominal oxide layers and the Si substrate.
@article{arxiv.2109.08586,
title = {Effect of Buffer Termination on Intermixing and Conductivity in LaTiO$_3$/SrTiO$_3$ Heterostructures Integrated on Si(100)},
author = {Tongjie Chen and Kamyar Ahmadi-Majlan and Zheng Hui Lim and Zhan Zhang and Joseph H. Ngai and Divine . P. Kumah},
journal= {arXiv preprint arXiv:2109.08586},
year = {2024}
}