Effect of Buffer Termination on Intermixing and Conductivity in LaTiO${}_3$/SrTiO${}_3$ Heterostructures Integrated on Si(100)

Abstract

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, LaTiO${}_3$(LTO) grown epitaxially on SrTiO${}_3$(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 TiO${}_2$-terminated STO buffers is correlated with La/Sr exchange and the formation of metallic La${}_{1-x}$Sr${}_x$TiO${}_3$. 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.

References in corpus (4)

• Avoiding the polarization catastrophe in LaAlO3 overlayers on SrTiO3(001) through a polar distortion
• Optical Study of the Free Carrier Response of LaTiO3/SrTiO3 Superlattices
• The Mott insulator LaTiO_3 in heterostructures with SrTiO_3 is metallic
• Oxide 2D electron gases as a route for high carrier densities on (001) Si

Cited by in corpus (1)

• THz carrier dynamics in $SrTi{O}_3/LaTi{O}_3$ interface two-dimensional electron gases