In:
Journal of Applied Crystallography, International Union of Crystallography (IUCr), Vol. 43, No. 2 ( 2010-04-01), p. 308-319
Abstract:
Single crystals of monoclinic Nd:LaVO 4 with dimensions up to Ø28 × 21 mm have been grown from the near-stoichiometric melt by the Czochralski method, making use of various seed orientations that are perpendicular to the (010), (10{\overline 1}), (001) and (00{\overline 1}) crystal planes. A sample was also prepared with the seed orientation in an arbitrary direction relative to the crystal. The anisotropic properties of the crystal are manifested in the growth morphology of the as-grown crystals, where different degrees of bulk spiral growth were observed. It was also found that employing the (001) or (00{\overline 1}) seed faces severely suppressed the bulk spiral growth, and thus high quality and large-scale Nd:LaVO 4 crystals were obtained. The constituent segregation coefficients and high-temperature stability, including the melting point, were determined and evaluated. Based on the attachment energy model of Hartman–Perdok theory, morphology predictions were made for monoclinic LaVO 4 and tetragonal YVO 4 orthovanadate single crystals. Correlating with the as-grown morphology of both crystals developed along different seed orientations, a theoretical explanation is provided for the influences of seed crystals on bulk spiral formation, crystal quality and utilization ratio. It suggests that breaking the axial symmetry of the ideal atomic level interface between crystal and melt plays a crucial triggering role in bulk spiral formation in the Czochralski growth of lanthanide orthovanadate single crystals. Selecting a proper seed orientation that yields such a highly axially symmetric surface structure consisting of a series of large-area facets with similar growth velocities can greatly reduce bulk spiral formation and thus is preferable in the Czochralski growth of large-sized low-symmetry oxide crystals.
Type of Medium:
Online Resource
ISSN:
0021-8898
DOI:
10.1107/S0021889809052339
DOI:
10.1107/S0021889809052339/wf5051sup1.cif
DOI:
10.1107/S0021889809052339/wf5051sup2.hkl
Language:
Unknown
Publisher:
International Union of Crystallography (IUCr)
Publication Date:
2010
detail.hit.zdb_id:
2020879-0
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