Figure 3.26 shows the first five peaks of the x-ray diffraction pattern for tungsten (W),...

Figure 3.26 shows the first five peaks of the x-ray diffraction pattern for tungsten (W), which has a BCC crystal structure; monochromatic x-radiation having a wavelength of 0.1542 nm was used.

(a) Index (i.e., give h, k, and l indices) each of these peaks.

(b) Determine the interplanar spacing for each of the peaks.

(c) For each peak, determine the atomic radius for W, and compare these with the value presented in Table 3.1.

Figure 3.26 Diffraction pattern for powdered tungsten. (Courtesy of Wesley L. Holman.)

Table 3.1 Atomic Radii and Crystal Structures for 16 Metals

aFCC = face-centered cubic; HCP = hexagonal close-packed; BCC = body-centered cubic.

bA nanometer (nm) equals 10–9 m; to convert from nanometers to angstrom units (Å), multiply the nanometer value by 10.