Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

1 Publication
Thermal expansion of polycrystalline gallium nitride: an X-ray diffraction study
Minikayev, R.; Paszkowicz, W.; Piszora, P.; Knapp, M.; Bähtz, C.; Podsiadlo, S.;
Gallium nitride is studied at ambient and nonambient temperatures by powder X-ray diffraction followed by Rietveld refinement of the structure. The structure is reported for the ambient temperature on the basis of laboratory data. The diffraction data collected using a synchrotron beam serve for derivation of the lattice parameter and thermal expansion dependencies on temperature. The variation of unit-cell size on temperature was studied in detail in a broad range 11 K < T < 1073 K. The obtained dependencies of a, c and V and thermal expansion coefficients are smooth, and the results are consistent with previously collected data. The c/a ratio shows an almost linear decreasing trend with rising temperature. The magnitude of thermal expansion obtained in the described experiments is similar to a recently reported theoretical one.
Keywords: Thermal expansion, x-ray diffraction, gallium nitride

Publ.-Id: 23212 - Permalink