Authors:T. Furuki, R. Abe, H. Kawaji, T. Atake, and M. Sakurai
The phase transitions of α,α-trehalose dihydrate (Th) were investigated by either differential thermal analysis (DTA) with an in-house apparatus of variable-pressure type equipped
with an open sample holder or commercially available TG (thermal gravimetry)-DTA apparatus for comparison under the same experimental
conditions as to the heating rate (2°C min−1), the type of pan (open), and the particle size of Th (63 μm). The former DTA measurements were carried out under five different total pressures, 101, 75, 61, 48 and 35 kPa, which
provided quite helpful information necessary for confirmative assignments of the endothermic peaks due to either melting or
dehydration of Th. The usage of largely different amount of Th, 126 and 14 mg for the DTA and TG-DTA measurements respectively, led to their different DTA traces, showing that there were
largely different extents of the influence by the measured sample surface exposed to the surrounding atmosphere on its dehydration
behavior. In addition the high thermal sensitivity achieved with such mass of Th gave rise to an interesting discovery of an unidentified thermal event at 92°C prior to either melting or dehydration of
Authors:Bedřich Smetana, Simona Zlá, Aleš Kroupa, Monika Žaludová, Jaromír Drápala, Rostislav Burkovič, and Daniel Petlák
investigation is focused on the area close to the monovariant line in the phase diagram of Sn–Zn–Al ternary system ( Fig. 1 ). As this region of the Sn–Zn–Al phase diagram still deserves a lot of attention [ 3 – 11 ], the temperatures of phasetransitions were
Authors:Edward Mikuli, Marta Liszka-Skoczylas, Joanna Hetmańczyk, and Janusz Szklarzewicz
of picoseconds. On cooling, several phasetransitions take place in these compounds [ 7 – 11 ]. For example, [Ni(NH 3 ) 6 ](NO 3 ) 2 displayed four low temperature phases [ 8 – 10 ]. The phasetransition at T C1 , associated with the largest change
Authors:Ke Liu, Xiao-Lin Zhou, Hai-Hua Chen, and Lai-Yu Lu
]. Although several research groups have experimental and theoretically investigated the pressure induced phasetransitions in TiN using different methods. For example, Zhao et al. [ 13 ] investigated the behavior of TiN using axial X-ray diffraction under
Authors:D. Vollmer, J. Vollmer, R. Strey, H. Schmidt, and G. Wolf
Differential scanning microcalorimetric measurements on phase transitions in water-oil-surfactant mixtures are presented,
demonstrating that this method is highly sensitive towards small heat changes connected with structural transitions in the
samples. The values for the latent heat of phase transitions are determined and the results are compared with predictions
from mean field theory, emphasizing the role calorimetric experiments can play to identify the most important contributions
to the free energy describing the mixtures. Doing this, the present status of the understanding of temperature dependent phase
transitions in microemulsions is reviewed.
Authors:J. Hatta, M. Okada, S. Matuoka, and H. Yao
Using an ac calorimetric method, detailed behaviour of the heat capacity in dipalmitoyl-phosphatidylcholine-cholesterol system was studied in the cholesterol concentration less than 5 mol%. It was revealed that the heat capacity near the main transition was composed of at least four anomalies, i.e., multipeak took place in the heat capacity. This fact indicates that a simple theory explaining coexistence of two phases in two component systems does not work in the multipeak region. Then, relation between the multipeak heat capacity and the change of the ripple structure with the cholesterol concentration should be taken into account, when we consider thermodynamical behaviour of the systems.
has been investigated for almost two decades and its ambient and sub-ambient phases have been well characterized: it has an orthorhombic structure with space group Fdd 2 below its ferro-paraelectric phasetransition at T c = −126 °C, and a
properties and phasetransition temperatures of (NH 4 ) 2 Co(SO 4 ) 2 ·6H 2 O crystals have not previously been reported. Further, some questions about Tutton salts are still open, especially those related to the nature of their structural changes and their
Authors:M. Rodová, J. Brožek, K. Knížek, and K. Nitsch
Phase transitions in ternary caesium lead bromide (CsPbBr3) were studied by means of DSC, TMA and high temperature X-ray diffraction. The samples were prepared from the solution by
water evaporation and from the melt. on the DSC curves as well as on the temperature dependence of the lattice constants of
CsPbBr3 only two effects were found belonging to the earlier published phase transitions at 88 and 130C and no further effects.
Linear thermal expansion coefficient α of individual CsPbBr3 modifications were calculated from both TMA and high temperature X-ray diffraction. The structural parameters of the room
temperature orthorhombic phase were refined and the results are presented. CsPbBr3 prepared from the solution contained about 10% of CsPb2Br5 and so the DSC curve of pure CsPb2Br5 was also measured and an effect at a temperature of 68.5C was found.