Rare Earth Nanomaterials

Abstract

Nanometer (nm) is a measure of scale: 1 nm = 10⁻⁹ m or 1 nm = 10⁻³ μm. Generally, the term “nanoparticles” is used to refer to particles ranging in the size from 1 to 100 nm. At the end of 1974, Japan applied the term “nano” to technology, but it only started to be applied to materials during the 1980s. As early as 1861, with the establishment of colloid chemistry, researchers began to study colloidal systems (1–100 nm). Platinum black is made up of platinum nanoparticles. In 1967, Kubo et al. proposed the quantum confinement or limited domain theory of ultramicroparticles for the study of metal particles, thus facilitating the exploration of nanoscale particles by experimental physicists. In 1984, the Gleiter group in Germany first prepared nanocrystalline Pd, Cu, and Fe with clean surface interfaces by inert gas evaporation and in situ pressurization, and then found that CaF₂ nanocrystals and TiO₂ nanoceramics have good toughness at room temperature, offering a new approach to toughening ceramics.