相关论文: In situ visualization of Ni-Nb bulk metallic glass…
Amorphous silica deforms viscoplastically at elevated temperatures, as is common for brittle glasses. The key mechanism of viscoplastic deformation involves interatomic bond switching, which is known to be a thermally activated process. In…
For most silicates, controlling the crystallization - through the nucleation, growth, and stabilization of distinct crystalline phase - is critical to achieving the desired physical properties in the final glass-ceramic product. In this…
Phase selection in deeply undercooled liquids and devitrified glasses during heating involves complex interplay between the barriers to nucleation and the ability for these nuclei to grow. During the devitrification of glassy alloys,…
The results of studies of supercooling upon crystallization value of Bi, Sn and Pb nanosized particles on the Al substrate and between the Al layers have been presented. It has been shown the efficiency of usage of layered film systems for…
We carry out molecular dynamics (MD) and Monte Carlo (MC) simulations to characterize nucleation in liquid clusters of 600 Lennard-Jones particles over a broad range of temperatures. We use the formalism of mean first-passage times to…
We introduce a combined Restrained MD/Parallel Tempering approach to study the difference in free energy as a function of a set of collective variables between two states in presence of unknown slow degrees of freedom. We applied this…
The enhancement of surface diffusion (DS) over the bulk (DV) in metallic glasses (MGs) is well documented and likely to strongly influence the properties of glasses grown by vapor deposition. Here, we use classical molecular dynamics…
The two-step heat treatment method is used to measure the steady state crystal nucleation rate and induction time as a function of temperature in BaO.2SiO2 and 5BaO.8SiO2 glasses. For both glasses, the temperature for maximum nucleation…
Structural changes in a glass due to deformation are subtle and difficult to quantify using conventional imaging and diffraction techniques. Additionally, transmission electron microscopy (TEM) sample preparation using energetic ions often…
The preparation in thin film form of the known icosahedral phase in Ti-Ni-Zr bulk alloys has been investigated as a function of substrate temperature. Films were deposited by Pulsed Laser Deposition on sapphire substrates at temperatures…
Solidification control is crucial in manufacturing technologies, as it determines the microstructure and, consequently, the performance of the final product. Investigating the mechanisms occurring during the early stages of nucleation…
High quality hexagon plate-like Na3Bi crystals with large (001) plane surfaces were grown from a molten Na flux. The freshly cleaved crystals were analyzed by low temperature scanning tunneling microscopy (STM) and angle-resolved…
In Part I of this study, vibration assisted heat treatments of ZBLAN glass revealed irregular crystallization at higher vibration levels, attributed to intermittent loss of thermal contact between the sample and the inner silica ampoule…
Dielectric measurements at very low temperature indicate that in a glass with the eutectic composition BaO-Al$_2$O$_3$-SiO$_2$ a phase transition occurs at 5.84 mK. Below that temperature small magnetic fields of the order of 10 $\mu$T…
Polycrystalline Nd$_{1-x}$Eu$_{x}$NiO$_3$ ($0 \leq x \leq 0.5$) compounds were synthesized in order to investigate the character of the metal-insulator (MI) phase transition in this series. Samples were prepared through the sol-gel route…
Bulk metallic glass forms when liquid metal alloys solidify without crystalization. In the search for Iron-based bulk glass-forming alloys of the metal-metalloid type (Fe-B- and Fe-C-based), crystals based on the structural prototype C6Cr23…
We report a wavelike fracture pattern in a Zr-based bulk metallic glass that has been deformed under quasi-static uniaxial tensions at temperatures between room temperature (300 K) and liquid nitrogen temperature (77 K). We attribute this…
Metallic glasses exhibit fast mechanical relaxations at temperatures well below the glass transition, one of which shows little variation with temperature known as nearly constant loss (NCL). Despite the important implications of this…
We use molecular dynamics simulation to study the relationship between structure and dynamics in supercooled binary Lennard--Jones nanoparticles over a range of particle sizes. The glass transition temperature of the nanoparticles is found…
The potential utilization of two-stage sintering for the production of highly dense and pure nickel diniobate (Ni4Nb2O9) ceramics with low firing temperature was demonstrated. Effects of designed sintering conditions on phase formation,…