Journal of Crystal Growth 235 (2002) 327–332 Growth and characterization of crack-free scheelite calcium molybdate single crystal fiber L.B. Barbosa a, *, D.Reyes Ardila a , C. Cusatis b , J.P. Andreeta a a Instituto de F! ısica de S * ao Carlos, Dpto de F! ısica e Ci # encia dos Materiais, Universidade de S * ao Paulo, C.P. 369, 13560-590 CEP, S * ao Carlos, SP, Brazil b Laborat ! orio de ! Optica de Raios X e Instrumenta - c * ao, Dpto de F! ısica, Universidade Federal do Paran ! a, C.P. 19091, CEP 81531-990, Curitiba, PR, Brazil Received 17 September 2001; accepted 25 October 2001 Communicated by R. Kern Abstract High-optical and structural quality single-phase scheelite calcium molybdate (CaMoO 4 ) single crystal was grown by the floating zone-like technique named laser-heated pedestal growth. The optical quality of the as-grown crystal was characterized by optical microscopy and absorption measurements, whereas the structural quality was evaluated by X-ray rocking curve profile, X-ray phase contrast radiography and X-ray topography measurements. The structural refinement of X-ray powder diffraction data recorded from crushed crystals was used to check the formation of single phase CaMoO 4 . All the obtained results indicate that completely crack-free, single phase, clear and transparent CaMoO 4 crystal was grown. r 2002 Elsevier Science B.V. All rights reserved. PACS: 81.10.Fq; 61.10.Nz; 42.70.Hj Keywords: A1. X-ray diffraction; A3. Laser heated pedestal growth; B1. Calcium compounds 1. Introduction CaMoO 4 crystallizes at room pressure and temperature in the scheelite structure (tetragonal, space group I4 1 /a) with a unit cell containing 4 Ca 2+ ions and 4 (MoO 4 ) 2 tetrahedra (two formula units) being equivalent in pairs because of their S 4 symmetry [1]. It is isostructural with the well-known phosphor CaWO 4 and presents a change of space group from I4 1 /a to I2 1 /a at T c ¼ 52K that reflects their ferroelastic properties similar to isostructural BiVO 4 and LaNbO 4 compounds [2]. It has a refractive index and thermal conductivity higher than in CaWO 4 (2.0 and 39mW/cm 1C, respectively, compared to 1.91 and 30mW/cm 1C), that are desirable conditions to assure a lower threshold in laser applications [3]. It presents lasing characteristics and crystal anisotropy that are manifested very strongly in the luminescence spectra [4,5]. Its absorption edge is located at B340nm (3.9eV) [6]. CaMoO 4 crystal has been proposed as a dispersive element in electronically tunable laser *Corresponding author. E-mail address: luciara@if.sc.usp.br (L.B. Barbosa). 0022-0248/02/$-see front matter r 2002 Elsevier Science B.V. All rights reserved. PII:S0022-0248(01)01816-4