The binary phase diagram of NaNO 3 -KNO 3 was studied by differential scanning calorimetry (DSC) and high-temperature x-ray diffractometry. The solid solutions in the intermediate concentration phase appeared to be a mixture of the NaNO 3 -based solid solutions and KNO 3 -based solid solutions. This behavior below the solidus suggests that NaNO 3 -KNO 3 might well be regarded as a system with limited solid solubilities instead of a continuous series of solid solutions. The temperatures for the solidus and liquidus have been determined with consideration of limited terminal solid solutions. Two models, the Henrian solution and regular solution theory for NaNO 3 -based phase and the KNO 3 -based phase, respectively, were used to reproduce the solidus and liquidus of the phase diagram. The results are in good agreement with the DSC data. The thermodynamic properties for the NaNO 3 -based and KNO 3 -based solid solutions have been derived from an optimization procedure using the experimental data. The calculated phase diagram and optimized thermodynamic parameters are thermodynamically self-consistent. Thus, the limited solid solution model seems to be more consistent with the phase diagram obtained by DSC than the continuous solid solution model.
The Ta-Sn phase diagram shown in Fig. 1 was proposed by [2002Stu]. Two intermediate phases existing in this system both have very narrow homogeneity ranges because no shift from the calculated spectra was found in the XRD measurements. The periteictic decomposition temperature of Ta2Sn3 at 595 °C was adopted from [1971Bas]. Ta-Sn crystal structure data (Table 1) were given in [Massalski2], but the phase diagram was unknown.
The Si-Yb phase diagram of [Masslski2] schematically showed the existence of four intermediate phases. Figure 1 is the complete Si-Yb phase diagram determined by [2003Pal] and is based primarily on differential thermal analysis, x-ray diffraction, optical microscopy, and electron probe microanalysis. Si4Yb3 and Si4Yb5 were discovered for the first time in this work. Si-Yb crystal structure data are summarized in Table 1.
For Abstract see ChemInform Abstract in Full Text.
The Eu-Pd phase diagram in [Massalski2] was redrawn from [Moffatt] with an additional EuPd7 phase based on more recent information. The outline of the phase diagram is shown with dashed lines in Fig. 1. Solid lines in Fig. 1 show the Eu-Pd phase diagram assessed by [2001Du]. Because both [Moffatt] and [2001Du] used the same experimental data source [1974Ian], the two phase diagrams are similar. However, the diagram of [2001Du] based on thermodynamics may be a better presentation of the experimental data.
Ni-Zn (Nickel-Zinc) H. Okamoto [2003Oka] introduced that the Ni-Zn phase diagram shown in [Massalski2] has been thermodynamically analyzed by [2000Vas] and [2002Su].[2011Xio] improved the thermodynamic modeling of this system by taking into account the order-disorder transition in b phase.The calculated phase diagram is shown in Fig. 1.Table 1 shows Ni-Zn crystal structure data.
