Below the Hall-Petch Limit in Nanocrystalline Ceramics.

Reducing the grain size of metals and ceramics can significantly increase strength and hardness, a phenomenon described by the Hall-Petch relationship. The many studies on the Hall-Petch relationship in metals reveal that when the grain size is reduced to tens of nanometers, this relationship breaks down. However, experimental data for nanocrystalline ceramics are scarce, and the existence of a breakdown is controversial.

Electron backscatter diffraction study of hexagonal boron nitride growth on Cu single-crystal substrates.

Hexagonal boron nitride (h-BN) is an important material for the development of new 2D heterostructures. To enable this development, the relationship between crystal growth and the substrate orientation must be explored and understood. In this study, we simultaneously grew h-BN on different orientations of Cu substrates to establish the impact of substrate structure on the growth habit of thin h-BN layers.

Growth and spectroscopic characterization of monolayer and few-layer hexagonal boron nitride on metal substrates.

Atomically thin two dimensional hexagonal boron nitride (2D h-BN) is one of the key materials in the development of new van der Waals heterostructures due to its outstanding properties including an atomically smooth surface, high thermal conductivity, high mechanical strength, chemical inertness and high electrical resistance. The development of 2D h-BN growth is still in the early stages and largely depends on rapid and accurate characterization of the grown monolayer or few layers h-BN films. This paper demonstrates a new approach to characterizing monolayer h-BN films directly on metal substrates by grazing-incidence infrared reflection absorption spectroscopy (IRRAS).