Scientists at the U.S. Department of Energy’s Ames Laboratory and their collaborators from Iowa State University have developed a new approach for generating layered, difficult-to-combine, heterostructured solids.
美國能源部所屬艾姆斯實驗室的科學家，及其來自美國愛荷華州立大學的共同研究人員們業已研發出一種，產生分層、難以組合的異質結構固體。
Heterostructured materials, composed of layers of dissimilar building blocks display unique electronic transport and magnetic properties that are governed by quantum interactions between their structurally different building blocks, and open new avenues for electronic and energy applications.
由不同構材層組成的異質結構材料展現了，由其結構上不同構材間，量子交互作用所左右的獨特電子傳輸及磁屬性。因此，為電子及能量應用開啟了新途徑。
(圖援用自原文)
The technique for making them is simple, and counterintuitive—it involves smashing the pristine materials to build new ones. Called mechanochemistry, the technique uses ball milling to take apart structurally incommensurate solids— ones that don’t have matching atomic arrangements— and reassemble them into unique three dimensional (3D) “misfit” hetero assemblies.
製造它們的技術是簡單且反直觀的，這涉及打碎原始材料來形成新材料。這種被稱為機械化學的技術，使用球磨方式來分解，結構上不相配的固體(沒有相配原子排列的固體)，並將它們重新組合成獨特三維(3D)的“不相配”異組合體。
Smashing things together by milling seems like the least plausible way to achieve atomic ordering, but it’s turned out to be more successful than the scientists themselves imagined.
藉由將東西粉碎在一起，似乎是實現原子排序最不合理的方法。不過，事實證明，這比科學家們自己想像的更為成功。
“A colleague of mine remarked that our ideas would be either naive or brilliant,” said Viktor Balema, Ames Laboratory Senior Scientist. “Some time ago we discovered stochastic reshuffling of layered metal dichalcogenides (TMDCs) into 3D hetero-assemblies during mechanical milling. It came as a complete surprise to us and triggered our curiosity about the possibility of atomic ordering through mechanochemical processing.”
艾姆斯實驗室資深科學家，Viktor Balema宣稱：「我的一名同事説，我們的構想應該不是太天真，就是太卓越。不久前，我們發現在機械碾磨的時候，層狀金屬二硫族化物(TMDCs)隨機重新改組成3D異質-組合物。這是一件十足令我們訝異的事，因此觸發了我們，有關透過機械化學處理，使原子有序化之可能性的好奇心。」
Metal chalcogenides are often unique in their properties and uses. They can display remarkable electron transport behaviors ranging from complete lack of electrical conductivity to superconductivity, photo- and thermoelectric properties, mechanical pliability and, especially, the ability to form stable two-dimensional monolayers, three dimensional heterostructures, and other nano-scaled quantum materials.
金屬硫族化物在其屬性及用途上，通常是獨特的。它們能展現，範圍從完全缺乏導電性到超導性的卓越電子傳輸行為、光電及熱電屬性、機械柔韌性及特別是，形成穩定之二維單層、三維異質結構及其他奈米級量子材料的能耐。
"Nanostructures of misfit layered compounds (MLC) in the form of nanotubes, nanofilms (ferecrystals) and exfoliated sheets have been investigated for over a decade and offer a rich field of research and possibly also exciting applications in renewable energy, catalysis and optoelectronics, said Reshef Tenne of the Weizmann Institute of Science, Israel, and an expert in nanostructure synthesis.
以色列魏茲曼科學研究所的奈米結構物合成專家，Reshef Tenne宣稱：「以奈米管、奈米薄膜(鐵晶體)及片狀剝落形式，形成之不相配層狀化合物(MLC)的奈米結構物，一直被調查研究已經達超過十年，且提供豐富的研究領域。因此，在可再生能源、催化作用及光電子領域，也可能引發諸多應用。」
One obstacle for their large-scale application is the high temperature and lengthy growth processes, which are prohibitive for large scale applications. The mechanochemical process developed by the Balema group at Ames Lab, besides being stimulating scientifically, brings us one step closer to realize down-to-earth applications for these intriguing materials."
它們大規模應用的一項障礙，是高溫及漫長的生長過程。就大規模應用而言，這些是使人望而卻步的。該由艾姆斯實驗室，Balema團隊研發的機械化學方法，除了科學上的刺激之外，也使我們更近一步接近，實現此些引人好奇之材料的實際應用。」
Typically, these complex materials, especially ones with the most unusual structures and properties, are made using two different synthetic approaches. The first, known as top-down synthesis, employs two-dimensional (2D) building blocks to assemble them, using additive manufacturing techniques.
通常，此些複雜材料，特別是具有最不尋常結構及屬性的材料，是使用兩種不同合成方法製成的。第一種方法，採用二維(2D)構材來組合它們，被通稱為自頂向下合成的加成製造技術。
The second approach, broadly defined as bottom-up synthesis, uses stepwise chemical reactions involving pure elements or small molecules that deposit individual monolayers on top of each other. Both are painstaking and have other disadvantages such as poor scalability for use in real-world applications.
第二種方法，被廣泛定義為自下而上的合成，這是使用涉及純元素或將個別單層，沉積於彼此頂部之小分子的逐步化學反應。這兩者皆很費勁，且具有諸如在實際應用上，不佳的使用規模可變性等其他缺點。
The Ames Laboratory team combined these two methods into one mechanochemical process that simultaneously exfoliates, disintegrates and recombines starting materials into new heterostructures even though their crystal structures do not fit each other well (i.e. misfit).
該艾姆斯實驗室團隊，將上述兩種方法結合成一種，同時使原材料片狀剝落、分解及重組成，即使其晶體結構彼此不太吻合(也就是不相稱)之新異質結構的機械化學方法。
Theoretical (DFT) calculations, supported by the results of X-ray diffraction, scanning transmission electron microscopy, Raman spectroscopy, electron transport studies and, for the first time ever, solid state nuclear magnetic resonance (NMR) experiments, explained the mechanism of the reorganization of precursor materials and the driving forces behind the formation of novel 3D heterostructures during mechanical processing.
由X-射線衍射、掃描透射電子顯微鏡技術、拉曼光譜、電子傳輸研究及有史以來的首度固態核磁共振(NMR)實驗結果，支持之密度泛函數理論(DFT：Density Functional Theory)的理論計算解釋了，機械處理期間，前身材料的重組機制，及形成新三維異質結構幕後的驅動力。
“Solid-state NMR spectroscopy is an ideal technique for the characterization of powdered materials that are obtained from mechanochemistry,” said Aaron Rossini, Ames Laboratory scientist and professor of chemistry at Iowa State University. “By combining information obtained from solid-state NMR spectroscopy with other characterization techniques we are able to obtain a complete picture of the 3D heterostructures.”
愛荷華州立大學化學教授暨艾姆斯實驗室科學家，Aaron Rossini宣稱：「固態的核磁共振光譜技術是一種，從機械化學獲得之粉末狀材料特性描述的理想技術。藉由結合獲自固態核磁共振光譜技術的信息與其他特性描述技術，他們能夠獲得3D異質結構的完整圖像。」
原文網址：https://www.ameslab.gov/news/using-chaos-as-a-tool-scientists-discover-new-method-of-making-3d-heterostructured-materials
翻譯：許東榮
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