Phase transformations at the nanoscale display interesting and important differences from those which occur in the bulk of most materials systems. These differences occur in a large variety of transformations, including melting, solid state phase transformation, chemical ordering and disordering, and chemical and electrochemical transformations. They arise from both the thermodynamic contributi...

Nucleation takes place when a material becomes thermodynamically meta-stable with respect to its transformation to a new state or new crystal structure. Very often, the nucleation process dictates the microstructure of a material. Predicting the shape of a critical nucleus in solids has been a long-standing problem in solid state phase transformations. It is generally believed that nucleation i...

A dental Au–Ag–Cu–Pd alloy with a relatively low Au content and a high Cu/Ag content ratio was examined to determine the correlation between the microstructural changes by the spinodal decomposition and age-hardening behaviour using a hardness test, X-ray diffraction study, field emission scanning electron microscopy and energy-dispersive X-ray spectrometry. Separation of the parent α0 phase oc...

The polymorphic form-I of the fluconazole drug commonly crystallized from the solution phase could be obtained by the solid state transformation of form-II employing different process parameters. As received fluconazole-II drug melted at 138.4 degrees C. The molten drug undercooled almost to ambient temperature of 30 degrees C and solidified to a glassy mass which, on ageing for 48 h transforme...

Biolox® delta has been widely used in joint replacements thanks to its high strength and wear resistance. In this study, eleven Biolox® delta femoral head retrievals affected by metal transfer (MT) were analysed by Raman spectroscopy to estimate the tetragonal to monoclinic zirconia phase transformation, whose occurrence may compromise ceramic chemical stability and mechanical strength. The res...

Abstract: In the present study the effect of thermomechanical treatment (cold work and annealing) on the transformation behavior of NiTi shape memory alloys was studied. Differential scanning calorimetry was used to determine transformation temperature and its relation to precipitates and defects. Three alloys including Ti-50.3at.% Ni, Ti-50.5at.% Ni (reclamated orthodontic wires) and 50.6at...

The deformation behavior of self-ion-implanted amorphous-Si (a-Si) has been studied using spherical nanoindentation in both relaxed (annealed) and unrelaxed (as-implanted) a-Si. Interestingly, phase transformations were clearly observed in the relaxed state, with the load–unload curves from these samples displaying characteristic discontinuities and cross-sectional transmission electron microsc...

An extensive experimental screen, coupled with a computational study, revealed seven new solid-state forms of β-resorcylic acid. The known, stable polymorph II° shows a reversible phase transformation to the new, kinetically stable, probably disordered high temperature form I. The study provides a consistent picture of the solid-state of β-resorcylic acid.

Optical modulation of the crystal structure and materials properties is an increasingly important technique for functionalization of two-dimensional and layered semiconductors, where traditional methods like chemical doping are ineffective. Controllable transformation between the semiconducting (H) and semimetallic (T') polytypes of transition metal chalcogenide monolayers is of central importa...