TY - JOUR
T1 - The valence of Ru, Ce and Eu ions in the magneto-superconductor Eu1.5Ce0.5RuSr2Cu2O10
AU - Felner, I.
AU - Asaf, U.
AU - Godart, C.
AU - Alleno, E.
PY - 1999
Y1 - 1999
N2 - The superconducting (Tc ∼ 32 K) Eu1.5Ce0.5RuSr2Cu2O10 (Ru-2122) material is also magnetically ordered (TM ∼ 122 K) with TM » Tc. Superconductivity (SC) is confined to the CuO2 planes, whereas magnetism is due to the Ru sublattice. Mossbauer spectroscopy performed at 90 and 300 K on 151Eu shows a single narrow line with an isomer shift = 0.69(2) and a quadrupole splitting of 1.84 mm/s, indicating that the Eu ions are trivalent with a nonmagnetic J = 0 ground state. This is in agreement with X-ray-absorption spectroscopy (XAS) taken at LIII edges of Eu, Ce which shows that Eu is trivalent and Ce is tetravalent. XAS experiments at the K edge of Ru indicate that Ru is pentavalent. This indicates, that in the M-2122 system, SC exists only for pentavalent M ions such as Ta, Nb and Ru.
AB - The superconducting (Tc ∼ 32 K) Eu1.5Ce0.5RuSr2Cu2O10 (Ru-2122) material is also magnetically ordered (TM ∼ 122 K) with TM » Tc. Superconductivity (SC) is confined to the CuO2 planes, whereas magnetism is due to the Ru sublattice. Mossbauer spectroscopy performed at 90 and 300 K on 151Eu shows a single narrow line with an isomer shift = 0.69(2) and a quadrupole splitting of 1.84 mm/s, indicating that the Eu ions are trivalent with a nonmagnetic J = 0 ground state. This is in agreement with X-ray-absorption spectroscopy (XAS) taken at LIII edges of Eu, Ce which shows that Eu is trivalent and Ce is tetravalent. XAS experiments at the K edge of Ru indicate that Ru is pentavalent. This indicates, that in the M-2122 system, SC exists only for pentavalent M ions such as Ta, Nb and Ru.
KW - Magnetism
KW - Mossbauer spectroscopy
KW - Superconductivity
KW - X-ray absorption spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=9344245132&partnerID=8YFLogxK
U2 - 10.1016/S0921-4526(98)00945-4
DO - 10.1016/S0921-4526(98)00945-4
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AN - SCOPUS:9344245132
SN - 0921-4526
VL - 259-261
SP - 703
EP - 704
JO - Physica B: Condensed Matter
JF - Physica B: Condensed Matter
ER -