1. Lattice parameters and anisotropic thermal expansion of hexagonal boron nitride in the 10?297.5�K temperature range
- Author
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Slawomir Podsiadlo, Jerzy B. Pelka, Michael Knapp, T. Szyszko, and W. Paszkowicz
- Subjects
Materials science ,Analytical chemistry ,DESY ,General Chemistry ,Atmospheric temperature range ,Thermal expansion ,law.invention ,Crystallography ,Beamline ,Magazine ,law ,Lattice (order) ,General Materials Science ,Anisotropy ,Powder diffraction - Abstract
Lattice parameters for hexagonal boron nitride (hBN) were determined using X-ray powder diffraction at a synchrotron-radiation source (beamline B2, Hasylab/DESY, Hamburg) in the previously uninvestigated temperature range from 10 K up to 297.5 K. The relative change of a and c with rise of temperature in the studied range is anisotropic and amounts to about -0.05% and +0.82%, respectively. The corresponding increase of the unit-cell volume is 0.73%. The evaluated values of thermal expansion coefficients derived from the lattice-parameter dependences on temperature are generally consistent with earlier data determined by interferometryfor T≥82 K.
- Published
- 2002
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