Czochralski pulling of scheelite-type NaBi(WO4)(2) single crystals

Tetragonal scheelite-like (space group I4(1)/a) NaBi(WO4)(2) single crystal s have been pulled using the Czochralski method from a stoichiometric melt with pulling rates in the 0.8-4 mm/h range. Differential thermal analysis e xperiments show that the crystal melts congruently at 935 +/- 3 degrees C. The lattice parameters deduced from theta-2 theta X-ray diffractionn scans in powdered crystals are a = 5.30 Angstrom and c = 11.58 Angstrom. The tran sparency range of undoped crystals is 0.4-4.9 mu m. The neodymium incorpora tion to the lattice has been evidenced by optical absorption at room temper ature. The Nd concentration of the highest Nd-doped crystal prepared is 2.8 x 10(19) cm(-3) and the Nd segregation coefficient for this crystal is 1.5 . (C) 1999 Elsevier Science B.V. All rights reserved.