Solid-State Transformations in Metal Iodides

2008 ◽  
Vol 138 ◽  
pp. 29-42
Author(s):  
Steve C. Hansen ◽  
D. Kobertz
Keyword(s):  
Solid State ◽  
Phase Diagrams ◽  
Metastable Phases ◽  
Molecular Solids ◽  
Polymorphic Transformations ◽  
Metal Iodides

Numerous solid-state transformations occur in metal iodides. These transformations can be classified into three categories: polymorphic transformations, polytypic transitions and molecular solids. Many of the modifications of metal iodides involve metastable phases transforming into stable phases. Revisions to the In-I and Th-I phase diagrams are made based on data found in the literature.

scholarly journals Exploiting the Synergy of Powder X-ray Diffraction and Solid-State NMR Spectroscopy in Structure Determination of Organic Molecular Solids

2013 ◽  
Vol 117 (23) ◽  
pp. 12258-12265 ◽  
Author(s):  
Dmytro V. Dudenko ◽  
P. Andrew Williams ◽  
Colan E. Hughes ◽  
Oleg N. Antzutkin ◽  
Sitaram P. Velaga ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Structure Determination ◽  
Solid State Nmr ◽  
Molecular Solids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Quantitative Predictions from Solid-State Physics - What do Phase Diagram Calculators Want?

1982 ◽  
Vol 19 ◽  
Author(s):  
Malcolm Rand
Keyword(s):  
Phase Diagram ◽  
Heat Capacity ◽  
Solid State ◽  
Binary Systems ◽  
High Pressures ◽  
Magnetic Moments ◽  
Configurational Entropy ◽  
Metastable Phases ◽  
Solid State Physics ◽  
Metastable Compounds

ABSTRACTThe types of information required for the calculation of phase diagrams are discussed by considering the computation of typical ternary sections from the constituent binary systems. Such calculations require a knowledge of the Gibbs energy of transformation (lattice stabilities) and Gibbs energies of mixing of wholly metastable, as well as the stable phases in binary systems. Similarly, the stabilities of metastable compounds such as Fe7C3 would be required for computations in the C-Cr-Fe system.These requirements are compared to the information provided by solid-state theoreticians. Essentially such calculations provide enthalpy values at 0 K (or some unspecified temperature for semi-empirical models); however the lattice dynamics and configurational entropy of simple phases have been included in some recent computations. The importance of predicting the entropy and thus heat capacity of metallic phases - particularly metastable phases - is therefore emphasized. Identification of those contributions to the heat capacity which are responsible for the differences between metal polymorphs is discussed, particularly the formalism for magnetic and atomic ordering phenomena. Predictions of ordering temperatures and magnetic moments as a function of composition would be of considerable help for phase diagram calculations.Ab-initio calculations already have considerable success in predicting molar volumes of both stable and metastable phases, so that such information will undoubtedly be of considerable value in studying alloy behaviour at high pressures.

Phase relations in the system Na2ZnP2O7-Zn2P2O7

1995 ◽  
Vol 10 (8) ◽  
pp. 2017-2023 ◽  
Author(s):  
R.G. Grebenshchikov ◽  
G.A. Mikirticheva ◽  
V.I. Shitova ◽  
M.A. Petrova ◽  
A.S. Novikova ◽  
...  
Keyword(s):  
Solid State ◽  
Phase Diagrams ◽  
Metastable Phase ◽  
Intermediate Compound ◽  
Phase Relations ◽  
Glass Crystallization ◽  
English Transl ◽  
Subsolidus Phase ◽  
Congruently Melting ◽  
Two Phases

Data on phase relations in the system Na2ZnP2O7-Zn2P2O7 reported in the literature are scarce and contradictory. The system was first studied by Berul and Voskresenskaya [Russ. J. Inorg. Mater. (English transl.) 4 (12), 2129 (1968)], who established the existence of a congruently melting intermediate compound, Na8Zn6(P2O7)5. In the paper by Majling et al. [Chem. Zvesti. 28 (3), 294 (1974)], the system Na2ZnP2O7-Zn2P2O7 is considered to be eutectic. The subsolidus phase relations are represented by a mixture of two phases, terminal members of the system. The existence of the above-mentioned compound was not confirmed for this system. In the present work we studied the phase relations in the system Na2ZnP2O7-Zn2P2O7 on samples obtained by solid-state synthesis and glass crystallization. The sequence of crystallization of phases was investigated, and the equilibrium and metastable phase diagrams were constructed for the system.

Interaction in the systems Y2O3−Ln2O3 (Ln=Tb–Lu)

2021 ◽  
Vol 2021 (2) ◽  
pp. 72-78
Author(s):  
A. O. Makudera ◽  
◽  
S. M. Lakiza ◽  
Keyword(s):  
Phase Transformations ◽  
Phase Diagrams ◽  
Solid Solutions ◽  
System Component ◽  
Polymorphic Transformations ◽  
Lanthanide Oxides ◽  
Solid States ◽  
Polymorphic Modifications ◽  
Temperatures Of Phase Transformations ◽  
Binary Compounds

Based on the analysis of literature data from experimentally constructed phase diagrams of Y2O3 − Ln2O3 systems (Ln = Tb − Lu), as well as temperatures of polymorphic transformations of rare earth oxides (REE), tentative phase diagrams of Y2O3 − Ln2O3 systems (Ln = Tb − Lu) were constructed in wide intervals of temperatures and concentrations. Prediction of the binary phase diagrams structure of yttria − yttrium subgroup lanthanides systems was carried out on the basis of three principles: 1. Since double systems are formed by lanthanide oxides of one (yttrium) subgroup, it is very likely that in such systems continuous solid solutions will be formed between the components. 2. Intermediate binary phases are not formed in these systems. 3. The formation of continuous solid solutions occurs with a decrease in the temperatures of phase transformations in the solid state to a minimum shifted towards a lower transformation temperature of the system component. The forecast of the Y2O3 – Ln2O3 systems phase diagrams structure, where Ln = Tb – Lu, indicates the complete solubility of the components in the liquid and solid states. Binary compounds in the considered systems are not predicted. Phase transformations in the solid solutions on the basis of polymorphic modifications X, H, A, B and C of lanthanide oxides cascade at high temperatures by the peritectoid mechanism. Below 1850 °C regions of solid solutions with cubic C-structure of REE oxides are formed in the whole range of concentrations in the systems. Key words: REE oxides, yttria, polymorphs of REE oxides, phase diagram.

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