Abstract
Isovalent substitution of S by Se in LaOBiS2-xSex has a substantial effect on its electronic structure and thermoelectric properties. To investigate the possible role of BiS2 structural instability, we have studied the local structure of LaOBiS2-xSex () using temperature dependent Bi L3-edge extended x-ray absorption fine structure measurements. The results reveal that the local structure of the two compounds is significantly different. The BiS2 sub-lattice is largely distorted in LaOBiS2 (x = 0.0), with two in-plane Bi-S1 distances separated by ∼0.4 Å instead LaOBiSSe (x = 1.0) showing much smaller local disorder with two in-plane Bi-Se distances in the plane being separated by ∼0.2 Å. Temperature dependent study shows that the two Bi-S1 distances are characterized by different bond strength in LaOBiS2 (x = 0.0) while it is similar for the Bi-Se distances in LaOBiSSe (x = 1.0). The out of plane Bi-S2 bond is harder in LaOBiSSe indicating that the structural instability of BiS2 layer has large effect on the out-of-plane atomic correlations. The results suggest that the local structure of LaOBiS2-xSex is an important factor to describe differing electronic and thermal transport of the two compounds.
| Original language | English |
|---|---|
| Article number | 455703 |
| Journal | Journal of Physics Condensed Matter |
| Volume | 30 |
| Issue number | 45 |
| DOIs | |
| Publication status | Published - Oct 22 2018 |
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Keywords
- BiS-based materials
- effect of substitution
- local structure and bond characteristics
- structural instability
- temperature dependent EXAFS
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
Cite this
Suppression of structural instability in LaOBiS2-xSex by Se substitution. / Paris, E.; Mizuguchi, Y.; Wakita, Takanori; Terashima, Kensei; Yokoya, Takayoshi; Mizokawa, T.; Saini, N. L.
In: Journal of Physics Condensed Matter, Vol. 30, No. 45, 455703, 22.10.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Suppression of structural instability in LaOBiS2-xSex by Se substitution
AU - Paris, E.
AU - Mizuguchi, Y.
AU - Wakita, Takanori
AU - Terashima, Kensei
AU - Yokoya, Takayoshi
AU - Mizokawa, T.
AU - Saini, N. L.
PY - 2018/10/22
Y1 - 2018/10/22
N2 - Isovalent substitution of S by Se in LaOBiS2-xSex has a substantial effect on its electronic structure and thermoelectric properties. To investigate the possible role of BiS2 structural instability, we have studied the local structure of LaOBiS2-xSex () using temperature dependent Bi L3-edge extended x-ray absorption fine structure measurements. The results reveal that the local structure of the two compounds is significantly different. The BiS2 sub-lattice is largely distorted in LaOBiS2 (x = 0.0), with two in-plane Bi-S1 distances separated by ∼0.4 Å instead LaOBiSSe (x = 1.0) showing much smaller local disorder with two in-plane Bi-Se distances in the plane being separated by ∼0.2 Å. Temperature dependent study shows that the two Bi-S1 distances are characterized by different bond strength in LaOBiS2 (x = 0.0) while it is similar for the Bi-Se distances in LaOBiSSe (x = 1.0). The out of plane Bi-S2 bond is harder in LaOBiSSe indicating that the structural instability of BiS2 layer has large effect on the out-of-plane atomic correlations. The results suggest that the local structure of LaOBiS2-xSex is an important factor to describe differing electronic and thermal transport of the two compounds.
AB - Isovalent substitution of S by Se in LaOBiS2-xSex has a substantial effect on its electronic structure and thermoelectric properties. To investigate the possible role of BiS2 structural instability, we have studied the local structure of LaOBiS2-xSex () using temperature dependent Bi L3-edge extended x-ray absorption fine structure measurements. The results reveal that the local structure of the two compounds is significantly different. The BiS2 sub-lattice is largely distorted in LaOBiS2 (x = 0.0), with two in-plane Bi-S1 distances separated by ∼0.4 Å instead LaOBiSSe (x = 1.0) showing much smaller local disorder with two in-plane Bi-Se distances in the plane being separated by ∼0.2 Å. Temperature dependent study shows that the two Bi-S1 distances are characterized by different bond strength in LaOBiS2 (x = 0.0) while it is similar for the Bi-Se distances in LaOBiSSe (x = 1.0). The out of plane Bi-S2 bond is harder in LaOBiSSe indicating that the structural instability of BiS2 layer has large effect on the out-of-plane atomic correlations. The results suggest that the local structure of LaOBiS2-xSex is an important factor to describe differing electronic and thermal transport of the two compounds.
KW - BiS-based materials
KW - effect of substitution
KW - local structure and bond characteristics
KW - structural instability
KW - temperature dependent EXAFS
UR - http://www.scopus.com/inward/record.url?scp=85055598359&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85055598359&partnerID=8YFLogxK
U2 - 10.1088/1361-648X/aae501
DO - 10.1088/1361-648X/aae501
M3 - Article
C2 - 30265246
AN - SCOPUS:85055598359
VL - 30
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 45
M1 - 455703
ER -