TY - JOUR
T1 - Synthesis and study of Hg-based 1222-type superconducting cuprates (Hg, M)Sr2(Ln, Ce)2Cu2O(z)
AU - Kandyel, E.
AU - Yamamoto, A.
AU - Wen, J. G.
AU - Tajima, S.
N1 - Funding Information:
This work was supported by the New Energy and Industrial Technology Development Organization (NEDO) as Collaborative Research and Development of Fundamental Technologies for Superconductivity Applications under the New Sunshine Program administered by the Agency of Industrial Science and Technology (AIST) of the Ministry of International Trade and Industry (MITI) of Japan.
PY - 2000
Y1 - 2000
N2 - A novel series of '1222-type' copper oxides described by the formula (Hg, M)Sr2(Ln, Ce)2Cu2O2 (M = Ti, V, Cr, Mo, W, Re; and Ln = Sm, Eu, Gd, Dy, Ho, Er) have been synthesized under high pressure. The structure was determined by combination of X-ray powder diffraction, electron diffraction and high-resolution electron microscopy measurements. The materials are isostrucrural with (Pb, Cu)-1222, crystallizing in a tetragonal unit cell, space group I4/mmm. The compounds adopt the 1222-type structure with an intergrowth of three types of layers: oxygen-deficient perovskite (CuO5 pyramidal layers), double fluorite-type layers, and double rock-salt layers. A correlation between lattice parameters and effective ionic radii of the (Ln, Ce) site is determined for (Hg0.75W0.25)Sr2(Ln1.5Ce0.5)Cu2O(z), Ln = Sm-Er. Except for Cr-containing compound, bulk superconductivity is observed in all the synthesized compounds. The value of T(c) is related to both the effective ionic radius of the (Ln, Ce) site and the valence of the M-element. Among these compounds, the sample with nominal composition of (Hg0.75W0.25)Sr2(Gd1.5Ce0.5)Cu2O(z) recorded the highest T(c) up to 75 K. (C) 2000 Academic Press.
AB - A novel series of '1222-type' copper oxides described by the formula (Hg, M)Sr2(Ln, Ce)2Cu2O2 (M = Ti, V, Cr, Mo, W, Re; and Ln = Sm, Eu, Gd, Dy, Ho, Er) have been synthesized under high pressure. The structure was determined by combination of X-ray powder diffraction, electron diffraction and high-resolution electron microscopy measurements. The materials are isostrucrural with (Pb, Cu)-1222, crystallizing in a tetragonal unit cell, space group I4/mmm. The compounds adopt the 1222-type structure with an intergrowth of three types of layers: oxygen-deficient perovskite (CuO5 pyramidal layers), double fluorite-type layers, and double rock-salt layers. A correlation between lattice parameters and effective ionic radii of the (Ln, Ce) site is determined for (Hg0.75W0.25)Sr2(Ln1.5Ce0.5)Cu2O(z), Ln = Sm-Er. Except for Cr-containing compound, bulk superconductivity is observed in all the synthesized compounds. The value of T(c) is related to both the effective ionic radius of the (Ln, Ce) site and the valence of the M-element. Among these compounds, the sample with nominal composition of (Hg0.75W0.25)Sr2(Gd1.5Ce0.5)Cu2O(z) recorded the highest T(c) up to 75 K. (C) 2000 Academic Press.
KW - (Hg, M)-1222
KW - High-T(c) superconductors
KW - High-pressure synthesis
KW - Magnetic susceptibility
KW - X-ray powder diffraction
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U2 - 10.1006/jssc.2000.8869
DO - 10.1006/jssc.2000.8869
M3 - Article
AN - SCOPUS:0033635509
VL - 154
SP - 488
EP - 497
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
SN - 0022-4596
IS - 2
ER -