TY - JOUR
T1 - A 57Fe Mössbauer study on the FeSe and Fe(Se,Te) superconductors
T2 - Discontinuities in the hyperfine parameters at Tc
AU - Lindén, Johan Kaarle Mikael
AU - Rautama, Eeva Leena
AU - Karppinen, Maarit
AU - Yamauchi, Hisao
PY - 2012
Y1 - 2012
N2 - Polycrystalline samples of FeSe 0.82 and FeSe 0.5Te 0.5 were synthesized using a solid-state reaction route. Bulk superconductivity was confirmed using SQUID magnetometry. The onset of T c was at 8.0 K for FeSe 0.82 and 12.5 K for FeSe 0.5Te 0.5. Paramagnetic 57Fe Mössbauer spectra were recorded at temperatures between 5.4 and 320 K in transmission geometry. All spectra exhibited simple quadrupole splitting. For FeSe 0.5Te 0.5 a small drop in the quadrupole splitting was observed about T c upon cooling. Additionally, for both samples the isomer shift and the total absorption started to drop around T c, indicating a softening of the lattice. The drop is estimated to correspond to at least 60 K from the original Debye temperatures.
AB - Polycrystalline samples of FeSe 0.82 and FeSe 0.5Te 0.5 were synthesized using a solid-state reaction route. Bulk superconductivity was confirmed using SQUID magnetometry. The onset of T c was at 8.0 K for FeSe 0.82 and 12.5 K for FeSe 0.5Te 0.5. Paramagnetic 57Fe Mössbauer spectra were recorded at temperatures between 5.4 and 320 K in transmission geometry. All spectra exhibited simple quadrupole splitting. For FeSe 0.5Te 0.5 a small drop in the quadrupole splitting was observed about T c upon cooling. Additionally, for both samples the isomer shift and the total absorption started to drop around T c, indicating a softening of the lattice. The drop is estimated to correspond to at least 60 K from the original Debye temperatures.
KW - Fe Mössbauer spectroscopy
KW - Chalcogenide superconductivity
KW - Iron-based superconductors
UR - http://www.scopus.com/inward/record.url?scp=84859598472&partnerID=8YFLogxK
U2 - 10.1007/s10751-011-0482-6
DO - 10.1007/s10751-011-0482-6
M3 - Article
AN - SCOPUS:84859598472
SN - 0304-3843
VL - 208
SP - 133
EP - 136
JO - Hyperfine Interactions
JF - Hyperfine Interactions
IS - 1-3
ER -