1 / 6

CHE 333 Class 23.

CHE 333 Class 23. Ceramics. Ceramic Structures. MIXTURES OF ELEMENTS Two Criteria for ceramic structures Electrical Neutrality using ionic charge cation (positive charge) must equal anion (negative charge) amounts. Eg NaCl Na one positive, Cl one negative

kalyca
Download Presentation

CHE 333 Class 23.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. CHE 333 Class 23. Ceramics

  2. Ceramic Structures MIXTURES OF ELEMENTS Two Criteria for ceramic structures • Electrical Neutrality using ionic charge cation (positive charge) must equal anion (negative charge) amounts. Eg NaCl Na one positive, Cl one negative 2. Cations (+ve) – usually smaller, contact Anions (-ve) in structure. Determines the coordination number of the structure for ceramics. Within certain ranges only particular coordination numbers will accommodate the different sized ions contacting each other.

  3. AX Ionic Structures NaCl structure CN 6 CsCl structure CN 8 ZnS structure CN 4 All these have a 1 to 1 cation to anion ratio, but different coordination numbers.

  4. AnXm and AnBmXp Structure Calcium Flouride CaF2 Barium Titanate Piezoelectric material

  5. Ceramic Structures

  6. Glass Silica Tetrehedra Tetrahedral Structure SiO44- Si – O ionic ratio is 0.29 tetra CN Unit cell of silicates. High Crystobalite 1470 to 1710C

More Related