A modulated crystal structure in Rb(2)ZnX(4) (X = Cl, Br) - a neutron time-of-flight single-crystal study

作者：Gutmann M J^*; Petricek V; Daoud Aladine M A; Martin C Y

来源：Measurement Science and Technology, 2008, 19(3): 034005.

DOI：10.1088/0957-0233/19/3/034005

• incommensurate crystal structure
• single crystal neutron diffraction

Data on the two prototype modulated structures of Rb(2)ZnX(4) (X = Cl, Br) have been collected at 300 K for X = Br and 210 K for X = Cl on the time-of-flight (TOF) single-crystal Laue diffractometer SXD installed at ISIS. Both compounds show a modulated structure with a propagation vector very close to (0, 0, 0.3). Lists of Bragg reflection intensities were successfully extracted and corrected for absorption with the locally available SXD2001 data reduction program. In parallel, JANA2006 has been adapted to handle TOF data, including specific extinction models. Good refinements have been obtained for both compounds demonstrating the viability of the TOF Laue method to efficiently collect several thousands of fundamental and satellite reflections on modulated crystals with only a few crystal orientations, and quantitatively analyse them using JANA2006.

• 出版日期2008-3