Epitaxy on Demand

Abstract

Perovskite oxide heteroepitaxy is realized on the top of inorganic nanosheets that are covering the amorphous oxide surfaces of Si substrates. Utilizing pulsed laser deposition, thin films of SrRuO3 in a (001)pc and (110)pc orientation on nanosheets of Ca2Nb3O10 and Ti0.87O2 are grown, respectively. The two types of nanosheets are patterned to locally tailor the crystallographic orientation and properties of SrRuO3. The success of our approach is demonstrated by electron backscatter diffraction and spatial magnetization maps. An unprecedented control of perovskite film growth on arbitrary substrates is illustrated in this work, and the methods that are developed to deposit SrRuO3 thin films are a viable starting point for growth of artificial heteroepitaxial thin films that require a bottom electrode. Control is not just reached in the direction of film growth, as the crystal orientation and film properties are regulated laterally on the surface of micropatterned nanosheets. Local control of magnetic properties is illustrated, which holds out prospects for the fabrication of next‐generation devices like noncollinear magnetic random access memories.

Two‐Dimensional Metal Oxide and Metal Hydroxide Nanosheets: Synthesis, Controlled Assembly and Applications in Energy Conversion and Storage

“…[59d,163] Soon, a Langmuir-Blodgett (LB) approach to make densely covered monolayer nanosheet films was demonstrated. [168] Monolayer films have also been constructed from regularly shaped Co(OH) 2 nanosheets that tiled into a densely packed film owing to the regular hexagonal shape of the LDH-derived crystallites. The use of barriers to compress these monolayers to packing densities of 97-99% and the LB transfer of the monolayer film to an arbitrary substrate is quite similar to the conventional LB method involving the transfer of close-packed surfactant monolayers.…”

“…[155] Selective layer reactions can transform the typically crystallographically oriented multilayer nanosheet films into dense films of dissimilar composition. [168,176,178] Phases forming at low temperatures such as ZnO can be grown directly onto nanosheet covered plastic substrates. The film ultimately transformed into NaNbO 3 at > 450 °C.…”

Textured Manganite Films Anywhere

“…Another approach for complex oxides integration onto non-adapted substrates is the use of nanosheets (NS) as seed layer 35 . In this approach, NS created by an exfoliation process of layered oxides are transferred on low cost large-surface substrates as silicon or glass, providing the seed layer for the growth of complex oxide thin films independently on the bottom substrate material.…”

Growth control of RF magnetron sputtered SrRuO3 thin films through the thickness of LaNiO3 seed layers

“…SRO films deposited directly on SiO 2 /Si have islands morphology with RMS roughness of 15.2 nm, higher than that of other LNO-buffered SRO films, however, the value of SRO on LNO300 is as low as 5.1 nm. The reason for the influence of the seed layer on the morphology of SRO films may be that newly created interfaces play a critical role in the alteration of interfacial energies, which influences the nucleation and growth kinetics of SRO [23]. Yet, despite the LNO can partly smooth the surface of SRO films, islands were not completely suppressed in some randomly oriented films (e.g., SRO films on LNO150 and LNO200), which suggests that surface morphology may not be merely resulted from interfacial effects.…”