Question

Calculate the Millerindices of crystal planes which cut through the crystal axes at (i) (2a, 3b, c), (ii) ($\infty,$2b, c )

• A. 3, 2, 6 and 0, 1, 2
• B. 4, 2, 6 and 0, 2, 1
• C. 6, 2, 3 and 0, 0, 1
• D. 7, 2, 3 and 1, 1, 1

Answer 1

Answer: (A)

3, 2, 6 and 0, 1, 2

Answer 2

(i) x y z

2a 3b c Intercepts

$\frac{2a}{a}$ $\frac{3b}{b}$ $\frac{c}{c}$ Lattice parameters

$\frac{1}{2}$ $\frac{1}{3}$ $\frac{1}{1}$ Reciprocals

3 2 6 Multiplying by LCM (6)

Hence, the Miller indices are (3, 2, 6)

(ii) x y z

$\infty$ $2b$ $c$ Intercepts

$\frac{\infty}{a}$ $\frac{2b}{b}$ $\frac{c}{c}$ Lattice parameters

$\frac{1}{\infty}$ $\frac{1}{2}$ $\frac{1}{1}$ Reciprocals

0 1 2 Multiplying by LCM (2)

Hence, the Miller indices are (0, 1, 2).