Calcium carbonate crystallization in organisms often occurs through the transformation from the amorphous precursor. It is believed that the amorphous phase could be temporarily stabilized and stored, until its templated transition to the crystalline form is induced. Here we develop a bioinspired crystallization strategy that is based on the above mechanism. Amorphous calcium carbonate (ACC) sp...

Hydride formation was studied on Pd particles supported on SiO2, and the results were evaluated with reference to a corresponding ZnO-promoted Pd/SiO2 catalyst reported recently. Pd particles (mean size, ~5 nm) were epitaxially grown on NaCl(001) cleavage faces and subsequently covered by a layer of amorphous SiO2, thereby maintaining their epitaxial orientation. The films were subjected to var...

The high-pressure behaviors of nitrogen-rich 1H-tetrazole (CH2N4) have been investigated by in situ synchrotron X-ray diffraction (XRD) and Raman scattering up to 75 GPa. A first crystalline-to-crystalline phase transition is observed and identified above ~3 GPa with a large volume collapse (∼18% at 4.4 GPa) from phase I to phase II. The new phase II forms a dimer-like structure, belonging to P...

Phase change materials based on chalcogenides are key enabling technologies for optical storage, such as rewritable CD and DVD, and recently also electrical nonvolatile memory, named phase change memory (PCM). In a PCM, the amorphous or crystalline phase affects the material band structure, hence the device resistance. Although phase transformation is extremely fast and repeatable, the amorphou...

An understanding of water's anomalies is closely linked to an understanding of the phase diagram of water's metastable noncrystalline states. Despite the considerable effort, such an understanding has remained elusive and many puzzles regarding phase transitions in supercooled liquid water and their possible amorphous proxies at low temperatures remain. Here, decompression of very high density ...

We investigate the amorphous structure, chemical bonding, and electrical properties of magnetron sputtered Fe(1-xCx) (0.21 ⩽ x ⩽ 0.72) thin films. X-ray, electron diffraction and transmission electron microscopy show that the Fe(1-xCx) films are amorphous nanocomposites, consisting of a two-phase domain structure with Fe-rich carbidic FeC(y), and a carbon-rich matrix. Pair distribution function...

Understanding the atomic structure of amorphous solids is important in predicting and tuning their macroscopic behavior. Here, we use a combination of high-energy X-ray diffraction, neutron diffraction, and molecular dynamics simulations to benchmark the atomic interactions in the high temperature stable liquid and low-density amorphous solid states of hafnia. The diffraction results reveal an ...

Amorphous arsenic sulphide As2S3 films prepared by ultrafast pulsed laser deposition have been vacuum annealed at a range of different temperatures. Measurements of the glass transition temperature indicate that a crystallization process initiates at annealing temperatures around 170 °C. In combination with Raman scattering analysis, we conclude that phase separation is intrinsic for our as-dep...

The aim of this work is to elucidate the formation of the amorphous phase in the Cu-Zr binary alloy system. It was found that 1 mm diameter rods with a fully amorphous structure can be prepared in a relatively wide range of compositions. In contrast, the formation of 2 mm diameter rods was achieved only for the Cu64Zr36 alloy and in the range of Cu53Zr47 Cu50Zr50, which are compositions near th...

Although lateral thermal conduction in Ge2Sb2Te5 (GST) films can influence the performance of phase change memory (PCM), there are no data available for the in-plane thermal conductivity. This work measures both the in-plane and the out-of-plane thermal conductivities for the amorphous, face-centered-cubic, and hexagonal-close-packed phases of GST using two independent techniques. For crystalli...