In a paper published this week in Nature (“Freestanding crystalline oxide perovskites down to the monolayer limit”), materials science researchers at the University of California, Irvine and other institutions unveil a new process for producing oxide perovskite crystals in exquisitely flexible, free-standing layers.
A two-dimensional rendition of this substance is intriguing to scientists and engineers, because 2D materials have been shown to possess remarkable electronic properties, including high-temperature superconductivity. Such compounds are prized as potential building blocks in multifunctional high-tech devices for energy and quantum computing, among other applications.
“Through our successful fabrication of ultrathin perovskite oxides down to the monolayer limit, we’ve created a new class of two-dimensional materials,” said co-author Xiaoqing Pan, professor of materials science & engineering and Henry Samueli Endowed Chair in Engineering at UCI. “Since these crystals have strongly correlated effects, we anticipate they will exhibit qualities similar to graphene that will be foundational to next-generation energy and information technologies.”
For all of their promising physical and chemical properties, oxide perovskites are difficult to render in flat layers due to the clunky, strongly bonded structure of their crystals. Earlier efforts at making free-standing, monolayer films of the material through the pulsed laser deposition method failed.
Pan’s cross-disciplinary group of researchers applied a technique called molecular beam epitaxy to grow the thin oxide films layer by layer on a template with a water-dissolvable buffer, followed by etching and transfer.
“Most of the known two-dimensional materials can be synthesized by exfoliation or by chemical deposition, as their bulk crystals consist of unique layered structures in which many strong covalently bonded planes are held together by weak van der Waals interactions,” he said. “But oxide perovskite is different; like most oxide materials, it has strong chemical bonds in three dimensions, making it especially challenging to fabricate into two dimensions.”

Image Credit:  YuXiaoqing Pan / UCI

Read more at nanowerk.com

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