Diagram Example : Diagram for Ca-B-O system at pO2(g)=0.1 atm

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  Details   Description

The chemical potential diagram for the Ca-B-O system:

1. Diagram
   
   (1)The two dimensional diagram in the {log a(Ca)-log a(B)}-T plot.
   
   Since stable phases are shown as a function of temperature in a similar way to the normal phase diagram, some of phases exhibit the transformaitons changing state.
   In order to explicitly show those states in a different manner, CHD provides functions of selecting the respective color or paint style.
   
   
   
   
   (2) Without check in respective states
   When the Respective states is not checked, solid or solid/liquid materials will be shown as one species as given below.
   
   
   
   • MALT stores the gaseous species as the separate state so that the gaseous state is always separately shown if stable.
   • Note that a big difference can be seen between with and without Respective states concerning the shape of the stability region for each compound. Without respective states, the stable polygon will be obtained as a convex polygon so that precise borderline shape between two compounds will disappear. Thus, it is highly recomended to always select this respective states as checked.
   • The number of states for respective compounds is given between the state and the temperature range in the compound table in MALT.
   
   
2. Description
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   • The polyhedron approach of constructing chemical potential diagrams assumes that each compound/species consists of one state. In many cases, this assumption can applied without problems. Even so, in the cases where temperature dependence is targetted, this is not necessalily good assumption.
   • Particularly some solid compound data contain those for liquid state in the MALT database.
   • Thus, CHD provides one option concerning whether such different states are displayed or not. This selection will be made in the CHC Options general page and alse in the Dimension Part in the Fixation Diagram dialog as given belo.
   
   
3. Details
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   [System] MALT

   Search Compounds

   Selection of <Ca,O,H> system
   

   MALT

   Tools > CHD

   with CHD parameter of "/md"

   • CHD starts to do the first task of "Malt Direct."
     
   • For the non-aqueous system, the default setting was made to construct the Chemical Potential diagram at 298 K.
     
     
   • The present diagram needs to confirm the option for the respective states
     

   Project > CHD Option

   
   
   • The last option : respective state should be checked.
     
     
     
     
   • The respective state can be identified in daigram.
     The state number is set from the low temperature side like 5.1, 5.2 where 5 is the Compound number among the retrieved and transfered compound table.