In this work, hybrid atomistic-macroscale simulation is conducted to explore the crystallization and amorphization of Si surface in the situation of fast melting and solidification induced by ultrafast laser heating and heat conduction. Our work is focused on investigating the relationship between the amorphization threshold (Ec) and the laser pulse width (tg). An empirical correlation Ec 1⁄4 4...

The use of compound in amorphous forms is a promising approach to improve solubility of poorly water-soluble drugs. However, during storage, amorphous state can spontaneously transform to the lower energy crystalline form and this is a limiting factor for a large commercial use of drugs. In this paper, calcined hydrotalcite was employed to support amorphous celecoxib and several preparations at...

Abstract. High Energy solid state electron momentum spectroscopy (EMS) is capable of directly measuring spectral functions of ordered and disordered solid matter. In this paper we investigate the spectral functions for the group IV semiconductors Ge and Si. We attempt to resolve the electronic structure differences in amorphous, polycrystalline and crystalline atomic arrangements of the semicon...

Low- and high-frequency Raman experiments in the 5-200 cm(-1) and 600-1800 cm(-1) ranges were carried out in the crystalline and amorphous states of ibuprofen. Low-frequency investigations indubitably reveal the existence of a molecular disorder in the metastable phase (phase II), through the observation of quasielastic contribution below 30 cm(-1), and the absence of phonon peaks in the Raman ...

Casein phosphor-peptides-amorphous calcium phosphate (CPP-ACP) products have been widely used in the field of preventive dentistry. CPP exerts its main effect through binding and stabilizing calcium and phosphate ions (ACP) in an amorphous, non-crystalline state where they can enter enamel and enhance remineralization. The following article presents a background on these products, in addition t...

Time-resolved measurements of the spectral dielectric function reveal new information about ultrafast phase transitions induced by femtosecond laser pulses in Sb-rich amorphous GeSb films. The excitation generates a nonthermal phase within 200 fs. The dielectric function of this phase differs from that of the crystalline phase, contrary to previous suggestions of a disorder-to-order transition....