A Study of the Crystal Structure of Y3cd9zn2 Using X-ray Powder Diffraction

Open Access
Zhang, Haowei
Graduate Program:
Materials Science and Engineering
Master of Science
Document Type:
Master Thesis
Date of Defense:
January 09, 2015
Committee Members:
  • Earle Richard Ryba, Thesis Advisor
  • Rare-earth intermetallic
  • crystal structure determination
  • synchrotron radiation
The thesis describes the determination of crystal structure of the intermetallic compound Y3Cd9Zn2. At the beginning, Y3Cd9Zn2 was considered as a member of a larger family of binary and ternary RE3B11 compounds, which exhibit a variety of structure and ordering schemes. Powder X-ray diffraction data were obtained for the compounds Y3Cd9Zn2 using a Panalytical X’Pert diffractometer. A partial ab initial determination of the structure of Y3Cd9Zn2 using the charge flipping technique was carried out, and the results indicate a strong resemblance to the crystal structure of the RE13B58 family of compounds. Synchrotron radiation data were obtained from the 11-BM beamline at Argonne National Lab. The charge flipping result highly indicates the crystal structure of Y3Cd9Zn2 is similar with that of Y13Cd58. Patterson maps were calculated by using the extracted intensities from the synchrotron radiations data by Le Bail method. The comparison of structure between Y13Cd58 and Y3Cd9Zn2 indicates the similar crystal structure between these two compounds. The accurate model was obtained through Fourier methods. The model of Y3Cd9Zn2 was proved by Rietveld refinement using JANA 2006 software package. The weighted residue Rwp was reduced to 11.8%. The crystal structure of Y3Cd9Zn2 shows a strong disorder between Cd and Zn atoms.