Question

The correct statement(s) regarding F-centre is/are?

• A. Electron are held in the voids of crystals
• B. F-centre produces colour to the crystals
• C. Conductivity of the crystal increases due to F-centre
• D. None of the above

Answer 1

Answer: (A), (B), (C)

Conductivity of the crystal increases due to F-centre

F centre is a type of crystallographic defect. In this defect an anionic vacancy in a crystal is filled by one or more electrons, based on charge on the missing ion in the crystal. Electrons which are present in this vacancy tend to absorb light in a visible spectrum in such a way that the transparent material seems to be coloured.