Local and electronic structure of carbon and nitrogen atoms in oxycarbonitrate superconductors

• Published in: Physica. C, Superconductivity Vol. 363; no. 1; pp. 55 - 59
• Main Authors: Kurmaev, E.Z, Moewes, A, Zhigadlo, N.D, Takayama-Muromachi, E, Yarmoshenko, Y.M, Shamin, S.N, Nekrasov, I.A, Bureev, O.A, Ederer, D.L
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-10-2001
• Subjects: Chemical state of doping elements; High- Tc superconductors; Local electronic structure; X-ray fluorescence measurements; Chemical state of doping elements; Local electronic structure; 78.70.En; High- T c superconductors; 74.72.Jt; 74.25.Jb; X-ray fluorescence measurements
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/S0921-4534(01)00613-X

Results of X-ray fluorescence measurements of new oxycarbonitrate superconductors
MSr
2Ca
n−1
Cu
n
O
y
(
n=1 or 2 and
M=Cu, C or N) are presented. The experiments show that C atoms form a distorted CO
3 oxyacid group with a partial substitution of copper and nitrogen atoms in the
M sites. Based on the comparison of nitrogen Kα emission spectra and spectra of reference samples it is concluded that the CO
3
2− group in (C,N)Sr
2Ca
n−1
Cu
n
O
y
and (Cu,C,N)Sr
2Ca
n−1
Cu
n
O
y
is substituted by the NO
2
− instead of the NO
3
− group. This induces the creation of hole carriers in these compounds.