Domain engineering of physical vapor deposited two-dimensional materials

Abstract

Physical vapor deposited two-dimensional (2D) materials span larger areas compared to exfoliated flakes, but suffer from very small grain or domain sizes. In this letter, we fabricate freestanding molybdenum disulfide (MoS2) and amorphous boron nitride (BN) specimens to expose both surfaces. We performed in situ heating in a transmission electron microscope to observe the domain restructuring in real time. The freestanding MoS2 specimens showed up to 100× increase in domain size, while the amorphous BN transformed in to polycrystalline hexagonal BN (h-BN) at temperatures around 600 °C much lower than the 850–1000 °C range cited in the literature.

(Project 13-5292) Correlating thermal and mechanical coupling based multiphysics behavior of nuclear materials through in-situ measurements

“…This is why the simultaneous effect of the current, temperature and stress is more pronounced than the individual stimuli. Our preliminary results also support that the synergy is more pronounced Alam et al (2014;Wang et al (2014) than the individual stimuli. It is important to note that the electrical annealing process is orders of magnitude faster than thermal annealing because of the very high atom drift velocity, (S2.10)…”

Structural Ordering of Molybdenum Disulfide Studied via Reactive Molecular Dynamics Simulations

“…14 Broadly speaking, for electronics, sensing and catalysis applications, wet-chemistry or chemical vapor deposition techniques are more often employed since they allow us to produce materials with tailored structural properties. On the other hand, in the tribological field, fabrication via magnetron sputtering is preferred, even though it generally offers less control over the crystallinity of the produced coatings (in some cases it leads to the growth of mixed crystalline structures [15][16][17][18][19][20] and in others to more amorphous materials [21][22][23][24][25] ).…”

In Situ Microstructural Control and Mechanical Testing Inside the Transmission Electron Microscope at Elevated Temperatures

“…A benign alternative could be to synthesize near-amorphous materials at low temperature and then engineer the grain size through the techniques presented above. 32 CONCLUSION TEM has been a workhorse for the materials and life sciences community. Through advances such as aberration correction, nano-beam diffraction and improved energy loss of filtering techniques, it has improved in resolution and analytical capabilities.…”