Phase Identification

The 'normal' method of phase identification uses the whole profile, and consists of the following steps:

1. Background modeling and subtraction, using BE button:

• • Left click for initial model.

  • Adjust via moving red dots (left button), adding red dots (shift-click), and deleting red dots (right click)

  • Remove background  (left clicking BE button -> Remove Background)

  • Right-clicking brings BE button with more options.

2. Searching for a matching pattern.

• • S/M button, keeping in mind which Database(s) are being searched.

We have three RDBs (Relational DataBases), which are subdivided

• • MDI-500: 500 common phases, provided with Jade (MDI = Materials Data Inc.)

  • MDI-mnd: 4447 8 line mineral files

  • PDF: (Powder Diffraction File - a proprietary database sold by the ICDD); we have the 2008 release of PDF-2. About 210,000 files, subdivided as follows:

    • Experimentally measured diffraction patterns:

      • Inorganics - 64274

      • Organics - 28045

      • Minerals - 7298

      • Metallics - 16983

    • Calculated diffraction patterns from crystal structures:

      • ICSD - Inorganic Crystal Structure Database - (Home is here: http://www.fiz-karlsruhe.com/icsd_home.html?&L=fmfkjnsgogka)

      • ALL - 96044

      • MIN - 14216

      • NIST (National Institutes of Standards and Technology) - 8502

            Note that the PDF is only accessible from the Data Analysis computer (the one on the left in the XRD room.)

• • AMCSD: (American Mineralogist Crystal Structure Database - a public domain database).

Notes:

• • Accurate background removal can have a large effect on the search.