Detailed Explanaion of Data

Considered matters:

• some difficulties were encountered during the optimization of their themodynamic properties in view of consistency with phase diagram behavior and other sources derived from the plausible kinetic effects behind the observed thermodynamic behaviors.
  
• Special remark should be needed for a particular compound with controvercial discussions.
  
• Special treatment was adopted for better understanding the behavior of a family of compounds such as perovskite compounds and related Ruddlesen Popper phases.
  
• Special treatment was adopted for high temperature heat capacities of gaseous or aqueous species to expnad the usability of compound data.
  

Focused Compounds/Properties

1. Perovskite Related Ruddlesen-Popper Phases
   • Those oxide compounds in the perovskite-type structure or related Ruddlesen-Popper phases exhibit the extensive solid solution behaviors among the family of compounds.
   • This makes attractive to treat this type of families as the ideal associated solutions. For such a purpose, chemical formula has been changed like A1.5BO3.5 instead of A3B2O7 and AB0.75O2.5 instead of A4B3O10.
   • This is due to the fact that the mixing entropy in the ideal associated solutions strongly depends on the atom numbers in one molecule (the hypothetical component in the solution).
   
   
2. Correlation of phosphates and related arsenatesand vanadates with ionic radii
   1. Correlation of alkaline earthe phosphates with ionic radii
      
      
   2. Correlation of alkaline earthe phosphates with ionic radii
      
      
   3. Correlation of alkali phosphates with ionic radii
      
      
   
   
3. About La2Zr2O7
   No change has been made, in spite of recent many investigations on the thermoynamic data of La2Zr2O7 after the first thermodaynamic evaluation was made in early 1990's. Detailed explanation was reported.
   
   
4. NaSiCon and related Phases in the Na-Zr-Si-P-O system
   OLd data for Nasicon was based on the electrochemical investigations (ref 162). New calorimetric inverstigation as well as the phase relation have been made extensively. Thus, attempts were made to evalute the thermodynamic data which are consistent with the experimental phase relations.
   
   
5. Li-Mn-O system
   • This system is famous in the technological field associated with the Li batteries. The materials behavior and electrochemical behaviors have been well investigated in the vicinity of room temperature, whereas the high temperature phase behaviors have been also extensively investigated. There can be some inconsistency among related information. The compiled thermodynamic data have been derived with understanding that the room temperature electrochemical characteristics are not necessarily in consistent with the most stable behaviors among compounds.
   
   
6. High Temperature Heat Capacity of Aqueous Species
   Recently, the heat capacities of aqueous species related with the geology have been evaluated uing a specialized heat capacity equation which is not consistent with the MALT adopted equations. Description is given to show how those coefficients of such equations can be transfered to those adopted in MALT database.
   
   
7. High Temperature Heat Capacity of Gaseous Species
   A large number of thermodynamic data for gaseous species have been determined by the high temprature Mass Spectrometry. However, in many cases, only the enthalpy of formaiton at 298 K or 0K are given withuot entropy or heat capacity information. Some attempts have been made to provide estimated values by simple considerations.
   
   
8. High Temperature Alloys
   Only a limited number of alloys are stored in the MALT database. This is beause that the MALT system has the strategy that the nonideal solutions are not treated and therefore only the intrmetallic compounds are stored. In a particular composition of alloy solution phase can be given to provide rough idea about the stability of the target alloy solutions.

MALT Main Menus   MALT Commands   MALT Dialogs