SOLID STATE PHYSICS
Fig. Q4 shows a hexagonal close packed structure (hep). (a) Show that for an ideal hop, = 2/1 = 1.633. . (8 marks) (b) Show that the packing ratio (or packing efficiency) of hcp is the same as that of foc structure, that is 0.74. (10 marks) (c) a-Co has an hep structure with lattice spacing a = 2.51 Å and c = 4.07 ), whereas B-Co is fec. What is the difference in density (in %) between the two forms? (Hint: a-Co obviously does not have ideal hep structure. Refer your answer in (b) to see how cla related to density) (6 marks) a Fig. 04 (d) Sodium transform from bcc to hcp at about T = 23K. Assuming that the density remain fixed and the c/a ratio is ideal, calculate the hcp lattice spacing a given that the cubic lattice spacing a' 4.23 in the bcc phase. (8 marks)
SOLID STATE PHYSICS
-
- Site Admin
- Posts: 899603
- Joined: Mon Aug 02, 2021 8:13 am