Abstract
We have studied the effect of Se substitution on Eu valence in a layered Eu0.5La0.5FBiS2-xSex superconductor using a combined analysis of x-ray absorption near-edge structure (XANES) and x-ray photoelectron spectroscopy (XPS) measurements. Eu L3-edge XANES spectra reveal that Eu is in the mixed valence state with coexisting Eu2+ and Eu3+. The average Eu valence decreases sharply from ∼2.3 for x=0.0 to ∼2.1 for x=0.4. Consistently, Eu 3d XPS shows a clear decrease in the average valence by Se substitution. Bi 4f XPS indicates that effective charge carriers in the BiCh2 (Ch = S, Se) layers are slightly increased by Se substitution. On the basis of the present results it has been discussed that the metallic character induced by Se substitution in Eu0.5La0.5FBiS2-xSex is likely to be due to increased in-plane orbital overlap driven by reduced in-plane disorder that affects the carrier mobility.
| Original language | English |
|---|---|
| Article number | 064515 |
| Journal | Physical Review B |
| Volume | 95 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Feb 27 2017 |
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ASJC Scopus subject areas
- Condensed Matter Physics
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Evolution of Eu valence and superconductivity in layered Eu0.5La0.5FBiS2-xSex system. / Mizuguchi, Y.; Paris, E.; Wakita, Takanori; Jinno, G.; Puri, A.; Terashima, Kensei; Joseph, B.; Miura, O.; Yokoya, Takayoshi; Saini, N. L.
In: Physical Review B, Vol. 95, No. 6, 064515, 27.02.2017.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evolution of Eu valence and superconductivity in layered Eu0.5La0.5FBiS2-xSex system
AU - Mizuguchi, Y.
AU - Paris, E.
AU - Wakita, Takanori
AU - Jinno, G.
AU - Puri, A.
AU - Terashima, Kensei
AU - Joseph, B.
AU - Miura, O.
AU - Yokoya, Takayoshi
AU - Saini, N. L.
PY - 2017/2/27
Y1 - 2017/2/27
N2 - We have studied the effect of Se substitution on Eu valence in a layered Eu0.5La0.5FBiS2-xSex superconductor using a combined analysis of x-ray absorption near-edge structure (XANES) and x-ray photoelectron spectroscopy (XPS) measurements. Eu L3-edge XANES spectra reveal that Eu is in the mixed valence state with coexisting Eu2+ and Eu3+. The average Eu valence decreases sharply from ∼2.3 for x=0.0 to ∼2.1 for x=0.4. Consistently, Eu 3d XPS shows a clear decrease in the average valence by Se substitution. Bi 4f XPS indicates that effective charge carriers in the BiCh2 (Ch = S, Se) layers are slightly increased by Se substitution. On the basis of the present results it has been discussed that the metallic character induced by Se substitution in Eu0.5La0.5FBiS2-xSex is likely to be due to increased in-plane orbital overlap driven by reduced in-plane disorder that affects the carrier mobility.
AB - We have studied the effect of Se substitution on Eu valence in a layered Eu0.5La0.5FBiS2-xSex superconductor using a combined analysis of x-ray absorption near-edge structure (XANES) and x-ray photoelectron spectroscopy (XPS) measurements. Eu L3-edge XANES spectra reveal that Eu is in the mixed valence state with coexisting Eu2+ and Eu3+. The average Eu valence decreases sharply from ∼2.3 for x=0.0 to ∼2.1 for x=0.4. Consistently, Eu 3d XPS shows a clear decrease in the average valence by Se substitution. Bi 4f XPS indicates that effective charge carriers in the BiCh2 (Ch = S, Se) layers are slightly increased by Se substitution. On the basis of the present results it has been discussed that the metallic character induced by Se substitution in Eu0.5La0.5FBiS2-xSex is likely to be due to increased in-plane orbital overlap driven by reduced in-plane disorder that affects the carrier mobility.
UR - http://www.scopus.com/inward/record.url?scp=85014588262&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85014588262&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.95.064515
DO - 10.1103/PhysRevB.95.064515
M3 - Article
AN - SCOPUS:85014588262
VL - 95
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 6
M1 - 064515
ER -