How Is Powder X-Ray Diffraction Analysis

3. RESULTS AND DISCUSSION
3.1. Powder X-Ray diffraction analysis The grown Cd doped LSMH crystal were subjected to powder X-ray diffraction studies using a Rich Seifert X-ray diffractometer employing CuKα (1.54058 Å) radiation, scanning angle ranging from 10° to 70° at a scan rate 1°/min to confirm the crystalline phase of the grown crystal. Fig 2 shows the X-ray powder diffraction patterns of pure as well as Cd doped LSMH single crystals. The obtained (h k l) values are indexed using the JCPDS software. It belongs to the monoclinic structure of space group is P21 and the lattice parameters are a=5.449 Å, b=4.832Å and c=8.137 Å & β =107.19˚ [JCPDS No. 840649]. The observed prominent peaks of Cd doped LSMH are (001), ( 01), (011), (101), (110),
532 nm laser was generated using Q-switched Nd:YAG laser of pulse width 7 ns and 10 Hz repetition rate was used for damage studies. The NS laser was focused by a convex lens of 100 mm focal length. The sample was kept 1 cm above to the focus of the laser for the measurements, where the spot size is 220 µm and the energy of the laser was measured using suitable energy power meter. The good transmission behavior and lower reflectance of the crystal proves that the laser induced damage on the crystal surface is always on the bottom side of the crystal. Initially ~15 mJ energy was applied on the conventional grown crystals and no damage was observed up to 30 s. When it is increased to ~20 mJ a small spot (~0.5 mm) appeared after 30 s on the surface of the sample. When it was further increased to ~30 mJ for 10 s, a crack appeared. The same experimental arrangement was allowed to measure LDT of the crystals grown from Cd doped LSMH and it was observed that the crystals could withstand up to ~25 mJ and no damage was noticed even after 30 s of exposure. When the energy of the laser energy increased to ~30 mJ, a small spot appeared on the surface of the crystal after 20 s. When the experiment was repeated with energy increased to 42mJ, the surface of the crystal cracked just after 10 s. Care was taken to select a fresh region after each shot to avoid cumulative effects resulting from multiple exposures. Fig. 4 shows photograph of typical laser damage sites in LSMH caused by 532 nm pulses of laser irradiation direction . The surface damage threshold of the crystal was calculated using the