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Title: Cation Substitution in Defect Thiospinels: Structural and Magnetic Properties of GaV4-xMoxS8 (0

Abstract

A new family of nonstoichiometric materials, GaV4-xMoxS8 (0=x=4), has been prepared and characterized by high-resolution neutron powder diffraction, laboratory and synchrotron X-ray powder diffraction, thermogravimetry, and SQUID magnetometery. All materials adopt a cubic (F3m) structure at ambient temperature. The end-member phases GaV4S8 and GaMo4S8 exhibit a distortion to rhombohedral (R3m) symmetry at low temperatures. High-resolution powder neutron diffraction reveals that the phase transition is incomplete and that both cubic and rhombohedral phases coexist below ca. 40 K. Magnetic susceptibility data indicate that at low temperatures, the end-member phases undergo a transition to a ferromagnetic state in which the metal-metal exchange interactions within cubic B4S4 clusters are predominantly antiferromagnetic in origin. At intermediate compositions (1=x=3) a cubic structure persists to 4 K, and materials remain paramagnetic to this temperature. The suppression of the rhombohedral distortion may be responsible for the absence of magnetic ordering observed in the nonstoichiometric members of the GaV4-xMoxS8 series.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
959648
Report Number(s):
BNL-82634-2009-JA
Journal ID: ISSN 0897-4756; CMATEX; TRN: US1005773
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Chemistry of Materials; Journal Volume: 19
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; AMBIENT TEMPERATURE; CATIONS; DEFECTS; DIFFRACTION; EXCHANGE INTERACTIONS; MAGNETIC PROPERTIES; MAGNETIC SUSCEPTIBILITY; NEUTRON DIFFRACTION; NEUTRONS; ORIGIN; SYMMETRY; SYNCHROTRONS; THERMAL GRAVIMETRIC ANALYSIS; national synchrotron light source

Citation Formats

Powell,A., McDowall, A., Szkoda, I., Knight, K., Kennedy, B., and Vogt, T. Cation Substitution in Defect Thiospinels: Structural and Magnetic Properties of GaV4-xMoxS8 (0. United States: N. p., 2007. Web. doi:10.1021/cm071354t.
Powell,A., McDowall, A., Szkoda, I., Knight, K., Kennedy, B., & Vogt, T. Cation Substitution in Defect Thiospinels: Structural and Magnetic Properties of GaV4-xMoxS8 (0. United States. doi:10.1021/cm071354t.
Powell,A., McDowall, A., Szkoda, I., Knight, K., Kennedy, B., and Vogt, T. Mon . "Cation Substitution in Defect Thiospinels: Structural and Magnetic Properties of GaV4-xMoxS8 (0". United States. doi:10.1021/cm071354t.
@article{osti_959648,
title = {Cation Substitution in Defect Thiospinels: Structural and Magnetic Properties of GaV4-xMoxS8 (0},
author = {Powell,A. and McDowall, A. and Szkoda, I. and Knight, K. and Kennedy, B. and Vogt, T.},
abstractNote = {A new family of nonstoichiometric materials, GaV4-xMoxS8 (0=x=4), has been prepared and characterized by high-resolution neutron powder diffraction, laboratory and synchrotron X-ray powder diffraction, thermogravimetry, and SQUID magnetometery. All materials adopt a cubic (F3m) structure at ambient temperature. The end-member phases GaV4S8 and GaMo4S8 exhibit a distortion to rhombohedral (R3m) symmetry at low temperatures. High-resolution powder neutron diffraction reveals that the phase transition is incomplete and that both cubic and rhombohedral phases coexist below ca. 40 K. Magnetic susceptibility data indicate that at low temperatures, the end-member phases undergo a transition to a ferromagnetic state in which the metal-metal exchange interactions within cubic B4S4 clusters are predominantly antiferromagnetic in origin. At intermediate compositions (1=x=3) a cubic structure persists to 4 K, and materials remain paramagnetic to this temperature. The suppression of the rhombohedral distortion may be responsible for the absence of magnetic ordering observed in the nonstoichiometric members of the GaV4-xMoxS8 series.},
doi = {10.1021/cm071354t},
journal = {Chemistry of Materials},
number = ,
volume = 19,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}