TY - JOUR
T1 - Anomalous heat capacity and x-ray photoelectron spectroscopy of superconducting FeSe1/2Te1/2
AU - Awana, V. P.S.
AU - Govind,
AU - Pal, Anand
AU - Gahtori, Bhasker
AU - Kaushik, S. D.
AU - Vajpayee, A.
AU - Kumar, Jagdish
AU - Kishan, H.
N1 - Funding Information:
Anand Pal, A. Vajpayee, and Jagdish Kumar thank the Council of Scientific and Industrial research (CSIR) India for a Senior Research Fellowship. Bhasker Gahtori is supported by the Department of Science and Technology (DST) fast track position (FTP) for young scientists.
PY - 2011/4/1
Y1 - 2011/4/1
N2 - The bulk polycrystalline sample FeSe1/2Te1/2 is synthesized via the solid state reaction route in an evacuated, sealed quartz tube at 750°C. The presence of superconductivity is confirmed through magnetization/thermoelectric/resistivity studies. It is found that the superconducting transition temperature (Tc) is around 12 K. The heat capacity (Cp) of superconducting FeSe1-xTe x exhibits a hump near Tc, instead of a well-defined lambda transition. X-ray photoelectron spectroscopy studies reveal well-defined positions for divalent Fe, Se, and Te, but with sufficient hybridization of the Fe (2p) and Se/Te (3d) core levels. In particular, divalent Fe is shifted to a higher binding energy, and Se and Te to a lower one. The situation is similar to that observed previously for the famous Cu-based high Tc superconductors, where the Cu (3d) orbital hybridizes with O (2p). We also found the satellite peak of Fe at 712.00 eV, which is attributed to the charge-carrier localization induced by Fe at the 2c site.
AB - The bulk polycrystalline sample FeSe1/2Te1/2 is synthesized via the solid state reaction route in an evacuated, sealed quartz tube at 750°C. The presence of superconductivity is confirmed through magnetization/thermoelectric/resistivity studies. It is found that the superconducting transition temperature (Tc) is around 12 K. The heat capacity (Cp) of superconducting FeSe1-xTe x exhibits a hump near Tc, instead of a well-defined lambda transition. X-ray photoelectron spectroscopy studies reveal well-defined positions for divalent Fe, Se, and Te, but with sufficient hybridization of the Fe (2p) and Se/Te (3d) core levels. In particular, divalent Fe is shifted to a higher binding energy, and Se and Te to a lower one. The situation is similar to that observed previously for the famous Cu-based high Tc superconductors, where the Cu (3d) orbital hybridizes with O (2p). We also found the satellite peak of Fe at 712.00 eV, which is attributed to the charge-carrier localization induced by Fe at the 2c site.
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U2 - 10.1063/1.3556682
DO - 10.1063/1.3556682
M3 - Article
AN - SCOPUS:79955458668
SN - 0021-8979
VL - 109
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 7
M1 - 07E122
ER -