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Synthesis and study of Sr-substituted misfit layer sulfides

Grippa, A. Yu ; Lidin, S. LU ; D'yachenko, O. G. ; Rupasov, D. P. and Antipov, E. V. (2005) In Materials Research Bulletin 40(1). p.79-91
Abstract

Two series of [(Ln1/3Sr2/3S)1.15] 1.15NbS2 (1.5Q/1H) and (Ln1- Sr S) 1+ NbS2 (1Q/1H) misfit layer sulfides have been synthesised and studied by X-ray powder and single crystal diffraction, EDX-analysis and magnetic measurements. For the early lanthanides (Ln = La, Ce) only the (Ln1- Sr S)1+ NbS2 (< 0.40-0.45, = 0.15-0.17) compounds were formed whereas for late lanthanides (Ln = Pr, Nd, Sm, Gd-Er, Yb, Lu), and yttrium, both types of phases can be obtained. The crystal structure of (Pr0.55Sr0.45S)1.15NbS 2 has been refined on the basis of X-ray single crystal data using the... (More)

Two series of [(Ln1/3Sr2/3S)1.15] 1.15NbS2 (1.5Q/1H) and (Ln1- Sr S) 1+ NbS2 (1Q/1H) misfit layer sulfides have been synthesised and studied by X-ray powder and single crystal diffraction, EDX-analysis and magnetic measurements. For the early lanthanides (Ln = La, Ce) only the (Ln1- Sr S)1+ NbS2 (< 0.40-0.45, = 0.15-0.17) compounds were formed whereas for late lanthanides (Ln = Pr, Nd, Sm, Gd-Er, Yb, Lu), and yttrium, both types of phases can be obtained. The crystal structure of (Pr0.55Sr0.45S)1.15NbS 2 has been refined on the basis of X-ray single crystal data using the superspace approach. It consists of double layers [Pr0.55Sr 0.45S] of NaCl-type (Q-part: = 5.799(3) Å, = 5.810(2) Å, = 23.331(9) Å, = 4) and NbS2-sandwiches (H-part: = 3.332(3) Å), = 8, yielding a q-vector q = (α 0 0), α = 0.74) alternating along the -direction. The superspace group pair is 2 (α 0 0): 2 (α 0 0) (No. 42.7). The refinement converged to w(obs) = 0.069. According to the structure refinement and EDX-analysis data in the [Pr0.55Sr0.45S]-slab almost half of the Pr-atoms are randomly replaced by Sr. The minimal formal value of charge transfer from the Q- to the H-part of the structure necessary to stabilise the misfit Nb-based layer sulfides has been estimated as about 0.6 ē per Nb atom.

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publishing date
type
Contribution to journal
publication status
published
keywords
A. Chalcogenides, A. Layer compounds, C. X-ray diffraction, D. Crystal structure, D. Magnetic properties
in
Materials Research Bulletin
volume
40
issue
1
pages
13 pages
publisher
Elsevier
external identifiers
  • scopus:10444228871
ISSN
0025-5408
DOI
10.1016/j.materresbull.2004.09.017
language
English
LU publication?
no
id
36035ea7-ab3c-4bd5-abd4-c46776ecfff5
date added to LUP
2019-04-08 15:23:02
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2020-07-08 04:47:22
@article{36035ea7-ab3c-4bd5-abd4-c46776ecfff5,
  abstract     = {<p>Two series of [(Ln<sub>1/3</sub>Sr<sub>2/3</sub>S)<sub>1.15</sub>] <sub>1.15</sub>NbS<sub>2</sub> (1.5Q/1H) and (Ln<sub>1-</sub> Sr S) <sub>1+</sub> NbS<sub>2</sub> (1Q/1H) misfit layer sulfides have been synthesised and studied by X-ray powder and single crystal diffraction, EDX-analysis and magnetic measurements. For the early lanthanides (Ln = La, Ce) only the (Ln<sub>1-</sub> Sr S)<sub>1+</sub> NbS<sub>2</sub> (&lt; 0.40-0.45, = 0.15-0.17) compounds were formed whereas for late lanthanides (Ln = Pr, Nd, Sm, Gd-Er, Yb, Lu), and yttrium, both types of phases can be obtained. The crystal structure of (Pr<sub>0.55</sub>Sr<sub>0.45</sub>S)<sub>1.15</sub>NbS <sub>2</sub> has been refined on the basis of X-ray single crystal data using the superspace approach. It consists of double layers [Pr<sub>0.55</sub>Sr <sub>0.45</sub>S] of NaCl-type (Q-part: = 5.799(3) Å, = 5.810(2) Å, = 23.331(9) Å, = 4) and NbS<sub>2</sub>-sandwiches (H-part: = 3.332(3) Å), = 8, yielding a q-vector q = (α 0 0), α = 0.74) alternating along the -direction. The superspace group pair is 2 (α 0 0): 2 (α 0 0) (No. 42.7). The refinement converged to <sub>w(obs)</sub> = 0.069. According to the structure refinement and EDX-analysis data in the [Pr<sub>0.55</sub>Sr<sub>0.45</sub>S]-slab almost half of the Pr-atoms are randomly replaced by Sr. The minimal formal value of charge transfer from the Q- to the H-part of the structure necessary to stabilise the misfit Nb-based layer sulfides has been estimated as about 0.6 ē per Nb atom.</p>},
  author       = {Grippa, A. Yu and Lidin, S. and D'yachenko, O. G. and Rupasov, D. P. and Antipov, E. V.},
  issn         = {0025-5408},
  language     = {eng},
  month        = {01},
  number       = {1},
  pages        = {79--91},
  publisher    = {Elsevier},
  series       = {Materials Research Bulletin},
  title        = {Synthesis and study of Sr-substituted misfit layer sulfides},
  url          = {http://dx.doi.org/10.1016/j.materresbull.2004.09.017},
  doi          = {10.1016/j.materresbull.2004.09.017},
  volume       = {40},
  year         = {2005},
}