Authors:Ying-Hui Shao, Xiao-Ning Ren, and Zi-Ru Liu
The eutectic binary phase diagrams of volatilizable energetic material 1,3,3-trinitroazetidine (TNAZ) with 1,3,5-trinitro-1,3,5-triazacyclohexane
(RDX) and 1-methyl-2,4-dinitroimidazole (MDNI) have been investigated by high pressure differential scanning calorimeter (PDSC),
respectively. The liquefying and melting processes of TNAZ/RDX and TNAZ/MDNI volatilizable systems have been studied. On the
basis of the data of apparent fusion heat and liquefying temperature, the phase diagrams of apparent fusion heat (H) with composition (X) and liquefying temperature (T) with composition (X) were constructed, respectively. The results showed that the gasification or volatilization of easy volatile energetic materials
could be efficiently restrained by high pressure atmosphere, and the perfect and ideal phase diagrams can be constructed.
The eutectic temperatures for TNAZ/RDX and TNAZ/MDNI are measured to be 95.5 and 82.3 °C, respectively. The eutectic compositions
of mole ratios for the two systems are obtained to be 93.55/6.45 (T–X method), 93.79/6.21 (H–X method) and 62.25/37.75 (T–X method), 63.29/33.71 (H–X method), respectively.
The thermotropic phase solid–solid transitions compound (n-CnH2n+1NH3)2ZnCl4 (n = 14, 16, 18) were studied, and a series of their mixtures were prepared. These laminar materials contain bilayers sandwiched
between metal halide layers. The low temperature crystal structures of the pure salts are characteristic of the piling of
sandwiches in which a two-dimensional macro-anion ZnCl42− is sandwiched between two alkylammonium layers. These layers become conformationally disordered in the high temperature phases.
The subsolidus binary phase diagrams of (n-C14H29NH3)2ZnCl4-(n-C18H37NH3)2ZnCl4 and (n-C16H33NH3)2ZnCl4-(n-C18H37NH3)2ZnCl4 were established by differential thermal analysis and X-ray diffraction. In each phase diagram, an intermediate compound
and two eutectoid invariants were observed. There are three noticeable solid solution ranges (α, β, γ) at the left boundary,
right boundary, and middle of the phase diagram.
Authors:F. Martínez Casado, M. Ramos Riesco, and J. Cheda
The temperature and enthalpy vs. composition diagrams of the binary
where x=mole fraction, were determined
by differential scanning calorimetry (DSC). This binary systems displays the
formation of two mixed salts with a composition 1:1 and 1:2, which melt incongruently
at Tfus=590.5 K,
kJ mol–1, and congruently at Tfus=614.5
K, with ΔfusHm=20.2
kJ mol–1, respectively. The phase diagram
also presents an ionic liquid-crystalline phase in a wide temperature range:
In this work the effect of oxygen pressure on the primary crystallisation fields for REBa2Cu3O7-x(RE=Nd, Sm, and Eu) has been studied. A DTA apparatus has been modified in order to carry out analyses under gas pressure, so
the trend of temperatures of peritectic decomposition of the REBa2Cu3O7-xphases and of the eutectic equilibrium involving REBa2Cu3O7-x phases and flux mixture "Ba2Cu5O7" have been studied at oxygen pressures of 0.21, 1, and 10 atm. This showed that primary crystallisation fields spread at
the increase of the oxygen pressure and allowed us to calculate the enthalpies of reactions of REBa2Cu3O7-xphases too.
Authors:Masoud Nazarian-Samani, Ali Reza Kamali, Mahboobeh Nazarian-Samani, Roohallah Mobarra, and Saber Naserifar
Ni–B binaryphasediagram ( Fig. 1 ) [ 1 ] shows several intermetallics of NiB, m -Ni 4 B 3 , o -Ni 4 B 3 , Ni 2 B, and Ni 3 B, respectively. These intermetallics have found interesting applications such as
Differential scanning calorimetry (DSC) was used to construct phase diagrams of binary mixtures of alkylcyclohexanes and to
characterize metastable phases formed in the binary mixtures. The experimentally measured liquidus curves were compared to
the liquidus curves calculated using ideal solution theory. The measured phase diagrams of pentadecylcyclohexane/nonadecylcyclohexane
and octadecylcyclohexane/nonadecylcyclohexane binary mixtures are consistent with theoretical phase diagrams constructed based
on the assumption that these mixtures form eutectic systems. It was also observed that a metastable phase formed in some binary
mixtures of pentadecylcyclohexane/nonadecylcyclohexane under fast cooling conditions. It is hypothesized that this metastable
phase recrystallizes into the eutectic phase upon heating.
Authors:Ying Hui Shao, Xiao Ning Ren, Zi Ru Liu, and Xiang Zhang
constructed by calculating from the data of the five T – X binaryphasediagrams [ 11 – 13 ].
The four energetic materials used in this study are 3,4-dinitrofurazanfuroxan (DNTF) 1
Authors:S. Wacharine, D. Hellali, H. Zamali, J. Rogez, and M. Jemal
The phase transitions of RbNO3 and the binary phase diagram of (Cs,Rb)NO3 were investigated at atmospheric pressure, using simultaneous direct and differential thermal analysis, μDTA and DSC techniques. A fourth phase transition of RbNO3 has been observed at temperature near the melting point. The phase diagram of this system is characterised by a eutectic, two eutectoid and an azeotropic-like invariants. Three limited solid solutions and two continuous solid solutions have been detected at low temperature.