Question

For FCC if AB is just like the rock salt like structure then, A+ and B- are located at -

• A. $A^+$ - Tetrahedral voids ; $B^-$ - Corner
• B. $A^+$ - Corner and faces ; $B^-$ - Octahedral voids
• C. $A^+$ - Octahedral voids ; $B^-$ - Corner and faces
• D. $A^+$ - Corner and faces ; $B^-$ - Octahedral and tetrahedral voids

Answer 1

Answer: (C)

$A^+$ - Octahedral voids ; $B^-$ - Corner and faces

Answer 2

AB is just like NaCl. Thus twelve $A^+$ are at edges and 1 within body of fcc i.e. in octahedral voids and six $B^-$ at faces and 8 at corner.