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Journal of Thermal Analysis and Calorimetry
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 phase transitions were

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of picoseconds. On cooling, several phase transitions take place in these compounds [ 7 – 11 ]. For example, [Ni(NH 3 ) 6 ](NO 3 ) 2 displayed four low temperature phases [ 8 – 10 ]. The phase transition at T C1 , associated with the largest change

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]. Although several research groups have experimental and theoretically investigated the pressure induced phase transitions in TiN using different methods. For example, Zhao et al. [ 13 ] investigated the behavior of TiN using axial X-ray diffraction under

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Abstract  

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.

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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.

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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 phase transition at T c = −126 °C, and a

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properties and phase transition 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

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Abstract  

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.

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Journal of Thermal Analysis and Calorimetry
Authors: G. Wolf, E. Königsberger, H. Schmidt, L.-C. Königsberger, and H. Gamsjäger
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A description of phase transitions as recorded by differential scanning calorimetry (DSC) is given. A new numberN is defined asN=h′/h, whereh is the height of a transition peak for a mass of samplem and a heating rate †p andh′ is the height of the same peak for a mass2m or a heating rate2† p.N is theoretically derived in the case of isothermal and nonisothermal first order phase transitions and of a second order phase transition. The equivalence of mass and heating rate is proved. An example of the possible use ofN is given.

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