Evolution of the Ti/a-GelSi trilayer reactions has been investigated using transmission electron microscopy and Auger electron spectroscopy. Instead of amorphous phase formation, as usually observed in the Ti/Si bilayer reaction, the crystalline Ti,GeS is the first phase observed during the reaction. Preceding the equilibrium C5CTi(Si,Ge),, a substitutional solid solution type C49-Ti(Si,Ge), fo...

Gas hydrates are crystalline solids formed from mixtures of water and low molecular weight compounds, referred to as hydrate formers, that typically are gases at ambient conditions (1). Generally, hydrates are formed in the laboratory from two-phase systems by contacting a hydrate former or formers in the gas or liquid phase with liquid water and increasing the pressure until crystalline hydrat...

The infrared spectra of solid ammonia at different phases and the existence of a metastable phase have been in controversy for the last fifty years. In order to address this problem, we studied the infrared spectra of solid ammonia in an ultrahigh vacuum chamber at distinct temperatures. Having prepared amorphous ammonia at 10 K, we observed a transition from the amorphous phase to the cubic cr...

2014 Dynamic quantities are computed near the transition from the columnar to the crystalline phase. The enhancement from order parameter fluctuations of the viscosities 03BD1 and 03BD3 is found to be proportional to the first power of the correlation length. We briefly describe how the 03C9-1/2 divergence of viscosities predicted in the columnar phase by Ramaswamy and Toner is suppressed near ...

Ge2Sb2Te5 and related phase change materials are highly unusual in that they can be readily transformed between amorphous and crystalline states using very fast melt, quench, anneal cycles, although the resulting states are extremely long lived at ambient temperature. These states have remarkably different physical properties including very different optical constants in the visible in strong c...

The α to β phase transformation of PVDF through the stretching process at different temperatures was investigated. The optimum stretching conditions were studied and characterised by infrared spectroscopy and differential scanning calorimetry. The maximum β−phase content was achieved at 80oC and a stretch ratio of 5. Accompanying the phase transformation, a orientation of the polymer chains and...

Amorphous materials are often preferred in the pharmaceutical industry due to their enhanced dissolution rate and bioavailability. Since the amorphous state is metastable and less thermodynamically stable relative to the crystalline state, there is always the potential for unexpected crystallization during storage. Conversion of amorphous to crystalline state can be evaluated by stability studi...

Ground and space born spectroscopic observations have shown that crystalline Mg-rich silicates are among the main components of cometary grains. We have produced amorphous Mg-rich pyroxene particles by laser evaporation of natural mineral. Thermal annealing of the material has been performed at 800 and 1000 ◦C for different time lags. Composition and morphological properties of the samples have...

We name strongly localized quantum crystalline state (SLQCS) a determinantal wave-function of the single-particle wave-functions obtained by crystalline translations of a wave-function different from zero only within a primitive cell of the considered quantum crystalline phase. SLQCSs accurately reproduce the low density behaviour of the quantum crystals that, as Wigner’s crystalline phase of t...

We demonstrate that crystalline color superconductivity may arise as a result of pairing between massless quarks and quarks with nonzero mass ms. Previous analyses of this phase of cold dense quark matter have all utilized a chemical potential difference δμ to favor crystalline color superconductivity over ordinary BCS pairing. In any context in which crystalline color superconductivity occurs ...