Attach1-Guidelines_PHASEDIAGRAMCommentaries2017.pdf

PHASE EQUILIBRIA DIAGRAMS

Guidelines for Preparation of COMMENTARIES

A. General Directions The commentary is a brief summary of the experimental or other work underlying the diagram and includes CRITICAL remarks as to its interpretation and application. Commentaries will not be considered acceptable for technical publication without an explicit judgment on the reliability of the accompanying diagram(s). Comparison of the work with other studies is recommended when necessary to support the editor’s opinion or to highlight unresolved differences between the current and previous works. If at all possible, please conclude your commentaries with a brief statement of the technological pertinence of the diagram and its chemical system.

The ideal commentary length for a single binary diagram is a single typed page, doubled-spaced, including references. Single ternary diagram commentaries can be from 1-2 pages, doubled-spaced. (A single commentary for multiple diagrams (same chemical system) may be somewhat longer overall, but generally the commentary length is governed by the experimental description which tends to be presented only once for a set of diagrams from a single work.)

Inclusion of tabular data (as for critical points and compositions) is not recommended if the same numerical data can be presented in the diagram itself or briefly included in the text. However, when necessary information would crowd the diagram and lessen its utility, a table is preferred to text if more than 3 or 4 points must be defined. See format under “Special Points” below.

If a paper contains diagrams for more than one chemical system, each chemical system (diagram) must have a separate commentary since these diagrams will not necessarily appear in the same portion of a volume. For example, a paper reporting a detailed study of the CaO-MgO-MnO2-SiO2 may include diagrams for the quaternary system as well as the subsystem ternaries or binaries, e.g. MgO-MnO2 - but these cannot be combined in a single commentary because the chemical system is not common. All diagrams published in one figure (commentary) must belong to the same chemical system. In this example a separate commentary would be needed for the MgO-MnO2 diagram in this paper. If the chemical system in a paper is the same for several diagrams, they may be included in one long commentary. The contributing editor’s judgment must determine the best way to present such diagrams. If multiple diagrams are included in one commentary the Figure Caption (and the text) must identify them as A, B, C, etc.

In general, discussion of features of the phase diagram which are obvious on the diagram itself (listing of compounds occurring in the system, etc.) is to be avoided where possible to keep the commentaries brief.

B. Style of Commentaries

The CRITICAL nature of the commentary is its major value to the user.

The formal description of the study should be sufficient for clear understanding by a practicing engineer or one familiar with the art.

Concentrate the commentary on the evaluation of the data (and experimental methods) and the resulting diagram; compare with other work as appropriate. The diagram must be evaluated as to its relative merit (i.e., “supersedes Fig. XXXX”) and/or limitations (“the location of the phase boundary of α ss using emf measurements was not confirmed by other characterization techniques and is considered approximate.”)

C. Contents of Commentaries

FIGURE CAPTIONS

Identify the end-members and the nature of the diagram, that is, “System BaO- MgO-TiO2. Isothermal section.” or “System NaCl-KCl. P-T diagram.”

In captions for binary diagrams, list the end-members from left-to-right. For ternary diagrams, list the end-members in counter-clockwise order beginning at the top of the triangle, although sometimes a clockwise order may be more chemically appropriate.

Define all abbreviations and symbols used in the diagram in the caption.

COMMENTARY TEXT

The following topics should be included whenever the information is available and their absence in the paper noted.

STARTING MATERIALS AND COMPOSITIONS

State the starting materials and their purity in terms of XX.XX% pure”. Do not use ambiguous terms such as “chemically pure” or “reagent grade” as these have no standard US or international meaning. (See Part D, “Matters of Style”, below).

For example, state “99.8% SiO2", not “chemically pure SiO2 (0.1 wt% TiO2, <0.02 wt% each Al2O3, Fe2O3, CaO, MgO)”. Specific impurities and their levels are stated only where significant to the attainment of equilibrium (for example, as a nucleating agent) or in the interpretation of the diagram (i.e., where the result is representative of industrial practice vs the research laboratory).

Purification methods (when used), pre-use characterization or treatments should be briefly described using a standard descriptor of technique (precalcining, vacuum distillation, pulverization, and homogenization, etc.)

Number and distribution of compositions examined should be simply stated, particularly if the present work builds on the work of others.

ex: “10 evenly-spaced compositions” or “20 compositions, from 0-25 mol% B, plus 10 compositions evenly-spaced from 30-100 mol% B” or “≈50 compositions, ≈25 clustered near critical points with ≈25 distributed across the diagram” or “10 compositions near AB2O4, were examined to clarify melting behavior. Other liquidus data is from the work of Ref. 2.”

CONTAINMENT

State the container or sample holder material used--if crucibles, were they closely or tightly covered; if tubes, were they welded or simply crimped, etc.; state the controlled atmosphere or that experiments were done in air.

APPARATUS AND TECHNIQUE

1. Give a condensed description of the type of experimental apparatus–DO

NOT USE COMPANY NAMES FOR ANY APPARATUS

a. heat source (Pt-wound resistance furnace, induction furnace, etc.);

b. method, precision and accuracy of temperature measurement and control-

- (examples: “temperature was measured within ±10°C using Pt-Pt10Rh thermocouples calibrated against the melting points of gold and palladium”; or “temperature was controlled to within ±2°C using a solid state proportional type controller”);

c. method of measuring partial pressures, or other important variables.

2. Briefly describe any special apparatus used important to the experiment--high-pressure apparatus; high-temperature X-ray; dilatometer, etc.

3. Briefly describe the technique, i.e., the manner in which the apparatus was used--how temperature run-up and cool-down was handled, etc.; for DTA, include heating and cooling rate, specimen size, etc.

4. State if the method of experimentation, time and duration of thermal treatment, atmosphere and quench method used are appropriate and likely to have produced an equilibrium result. This is of particular importance in solid state studies. This statement is a major critical factor in the evaluation of the value of the phase diagram.

CHARACTERIZATION OF EXPERIMENTAL PRODUCTS

1. State methods used to characterize the phases (i.e., microprobe, powder x-ray diffraction, etc.);

2. Give, where warranted, a description of the results (i.e., “the TEM investigation showed that all products were single phase”).

SPECIAL POINTS

1. For binary diagrams, give values of experimentally determined eutectics, peritectics, etc. only when not included on the diagram.

2. For ternary diagrams, give these values in the text.

a. If one or two invariant points are present, state them simply in sentence form, as “a eutectic at 425°C, 15% CaO-30%Al2O3-55%SiO2.”

b. If three or more invariant points are present, the preferred format is a table:

Temp. Composition (mol%) Type (°C) CaO Al2O3 SiO2 Eutectic (E1) 651 40 40 20 Eutectic (E2) 452 35 40 25 Peritectic 767 20 60 20 Minimum 900 60 20 20

Composition of critical points should be stated in terms of the components of the diagram as presented.

The tabular format will generally be needed only for ternary and higher-order diagrams. If necessary, an additional column naming the phases participating in the invariant equilibria can be included.

DISCUSSION

1. Compare this work with previous work on the same system and state whether it is consistent with other work; give the Figure No. if the diagram has been included in earlier volumes.

2. Note any areas of the diagram where alternative interpretations are possible within the limitations of the data.

3. State uncertainties associated with the equilibria shown on the diagram.

4. Indicate areas which need further study.

5. State limitations due to the experimental methods which may not be obvious and, therefore, should be pointed out.

6. Provide descriptive clarification of complex portions of the diagram if necessary.

7. Give experimental evidence for equilibrium or disequilibrium.

8. Discuss areas where the phase rule is not obeyed.

9. Discuss any models used in extrapolation.

10. For ternary and higher-order diagrams, include references to limiting binary diagrams if these have been studied.

GIVE CRITICAL ASSESSMENT OF RELIABILITY AND

USEFULNESS OF THE PHASE DIAGRAM

D. Matters of Style and Format

1. Use “mp” for melting point.

2. Always include units on data values in the text. For temperatures, use C or K; for pressures use Pa, MPa, or GPa; for composition, use mol% or wt%.

3. In designating thermocouples, use dashes, e.g; Pt-Pt10Rh.

4. When the purity of starting materials are not stated with actual limits or numerical values, use as a modifier CP (for chemically pure) or AR (for analytical reagent) if these ore equivalent terms are used in the text.

5. If you refer to “earlier work” in your commentary, give the reference(s).

List the full references as footnotes following the commentaries.

6. Designate all footnote references in the text either by numerical superscripts (“in earlier work”) or as Ref. 3 (“other data are in Ref. 3").

7. Refer to diagrams in earlier volumes of Phase Diagrams for Ceramists or Phase Equilibria Diagrams simply by figure number, i.e., Fig. 4052. No further identification is needed.

8. For bibliographic citations, please give the reference as completely as possible. The ACerS rules prescribe that we include issue number, not just a volume number for a journal entry, and the full range of pages for the reference. If a book or report, the full title, pages, chapters, authors, editors, publishers, etc. are needed. If this information is available, it saves the Data Center staff a great deal of time since the staff needs to check all the references.

9. Include the chemical composition in parentheses after a phase referred to by a mineral name (See Diagram Editing, Sect. A(4)).