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Title: Crystal growth, structure, and stoichiometry of the superconducting pyrochlore Cd2Re2O7.

Abstract

We report single-crystal growth of the superconducting pyrochlore Cd2Re2O7 using a vapor transport technique. Several parameters of the growth conditions, including hot-zone temperature and starting stoichiometry, were varied in order to control the formation of ReO2 inclusions, as confirmed by the electron microscopy, resistivity, and magnetic susceptibility measurements. The Rietveld refinement of x-ray (neutron) powder diffraction was found to be consistent with a cubic structure Fd3m with lattice constant a = 10.2250 (10.2358) A # and reduced coordinate of O1 = 0.3184 (0.3177) at 293 K (250 K). We also studied the oxygen stoichiometry by means of redox reactions, electron microprobe analysis (EMPA), and x-ray/neutron diffractions. Particularly, the neutron powder diffraction on the 114Cd-enriched specimens yielded an oxygen deficiency d = 0.14 # 0.03 solely at the O2 site, which was consistent with the EMPA results. The EMPA indicated that the oxygen deficiency is homogeneous in the bulk and in a range of 0.01 # 0.18#0.23 # 0.19.

Authors:
 [1];  [2];  [2];  [3];  [2];  [1]
  1. Clemson University
  2. ORNL
  3. Brookhaven National Laboratory (BNL)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
958830
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Electronic Materials; Journal Volume: 36; Journal Issue: 7
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CRYSTAL GROWTH; DIFFRACTION; ELECTRON MICROPROBE ANALYSIS; ELECTRON MICROSCOPY; MAGNETIC SUSCEPTIBILITY; NEUTRONS; OXYGEN; PYROCHLORE; REDOX REACTIONS; STOICHIOMETRY; TRANSPORT; Cd2Re2O7; pyrochlore; superconductor; neutron diffraction

Citation Formats

He, Jian, Jin, Rongying, Chakoumakos, Bryan C, Gardner, J. S., Mandrus, David, and Tritt, Terry M. Crystal growth, structure, and stoichiometry of the superconducting pyrochlore Cd2Re2O7.. United States: N. p., 2007. Web. doi:10.1007/s11664-007-0087-7.
He, Jian, Jin, Rongying, Chakoumakos, Bryan C, Gardner, J. S., Mandrus, David, & Tritt, Terry M. Crystal growth, structure, and stoichiometry of the superconducting pyrochlore Cd2Re2O7.. United States. doi:10.1007/s11664-007-0087-7.
He, Jian, Jin, Rongying, Chakoumakos, Bryan C, Gardner, J. S., Mandrus, David, and Tritt, Terry M. Mon . "Crystal growth, structure, and stoichiometry of the superconducting pyrochlore Cd2Re2O7.". United States. doi:10.1007/s11664-007-0087-7.
@article{osti_958830,
title = {Crystal growth, structure, and stoichiometry of the superconducting pyrochlore Cd2Re2O7.},
author = {He, Jian and Jin, Rongying and Chakoumakos, Bryan C and Gardner, J. S. and Mandrus, David and Tritt, Terry M.},
abstractNote = {We report single-crystal growth of the superconducting pyrochlore Cd2Re2O7 using a vapor transport technique. Several parameters of the growth conditions, including hot-zone temperature and starting stoichiometry, were varied in order to control the formation of ReO2 inclusions, as confirmed by the electron microscopy, resistivity, and magnetic susceptibility measurements. The Rietveld refinement of x-ray (neutron) powder diffraction was found to be consistent with a cubic structure Fd3m with lattice constant a = 10.2250 (10.2358) A # and reduced coordinate of O1 = 0.3184 (0.3177) at 293 K (250 K). We also studied the oxygen stoichiometry by means of redox reactions, electron microprobe analysis (EMPA), and x-ray/neutron diffractions. Particularly, the neutron powder diffraction on the 114Cd-enriched specimens yielded an oxygen deficiency d = 0.14 # 0.03 solely at the O2 site, which was consistent with the EMPA results. The EMPA indicated that the oxygen deficiency is homogeneous in the bulk and in a range of 0.01 # 0.18#0.23 # 0.19.},
doi = {10.1007/s11664-007-0087-7},
journal = {Journal of Electronic Materials},
number = 7,
volume = 36,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}