TY - JOUR
T1 - Systematic study on synthesis and structural, electrical transport and magnetic properties of Pb-substituted Bi-Ca-Co-O misfit-layer cobaltites
AU - Tanaka, Yoshiaki
AU - Fujii, Tatsuo
AU - Nakanishi, Makoto
AU - Kusano, Yoshihiro
AU - Hashimoto, Hideki
AU - Ikeda, Yasunori
AU - Takada, Jun
PY - 2007/1/1
Y1 - 2007/1/1
N2 - Single-phases of Pb-substituted Bi-Ca-Co-O misfit-layer cobaltites with various Pb concentrations have been synthesized and the Pb-substitution effects on the structural, electrical and magnetic properties have been systematically investigated. Powder X-ray diffraction analysis showed that the single-phases of Bi1.8-x/2PbxCa2Co2Oz were obtained up to x = 0.6 - 0.7 under the optimized synthesis conditions. The lattice parameters of Bi1.8-x/2PbxCa2Co2Oz continuously changed with increasing Pb concentration. The electron diffraction analysis suggested that the structure consisted of two different sublattices with a rock salt structure (RS) and a hexagonal CdI2 structure (H), respectively, without modulation. In combined with the chemical composition analysis, the chemical formulas of the x = 0 and x = 0.6 samples were determined approximately as [Bi1.74Co0.31Ca2.01O4]RS[CoO2]1.69 and [Bi1.47Pb0.38Co0.29Ca1.98O4]RS[CoO2]1.71, respectively. The electrical resistivity became more metallic with increasing the Pb concentration up to x = 0.6. Moreover, the Pb-substitution simultaneously increased the antiferromagnetic Weiss temperatures and decreased the effective magnetic moments of the Co ions.
AB - Single-phases of Pb-substituted Bi-Ca-Co-O misfit-layer cobaltites with various Pb concentrations have been synthesized and the Pb-substitution effects on the structural, electrical and magnetic properties have been systematically investigated. Powder X-ray diffraction analysis showed that the single-phases of Bi1.8-x/2PbxCa2Co2Oz were obtained up to x = 0.6 - 0.7 under the optimized synthesis conditions. The lattice parameters of Bi1.8-x/2PbxCa2Co2Oz continuously changed with increasing Pb concentration. The electron diffraction analysis suggested that the structure consisted of two different sublattices with a rock salt structure (RS) and a hexagonal CdI2 structure (H), respectively, without modulation. In combined with the chemical composition analysis, the chemical formulas of the x = 0 and x = 0.6 samples were determined approximately as [Bi1.74Co0.31Ca2.01O4]RS[CoO2]1.69 and [Bi1.47Pb0.38Co0.29Ca1.98O4]RS[CoO2]1.71, respectively. The electrical resistivity became more metallic with increasing the Pb concentration up to x = 0.6. Moreover, the Pb-substitution simultaneously increased the antiferromagnetic Weiss temperatures and decreased the effective magnetic moments of the Co ions.
KW - A. Misfit-later cobaltite
KW - D. Hole-doping
KW - D. Pb-substitution
UR - http://www.scopus.com/inward/record.url?scp=33751418654&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33751418654&partnerID=8YFLogxK
U2 - 10.1016/j.ssc.2006.10.015
DO - 10.1016/j.ssc.2006.10.015
M3 - Article
AN - SCOPUS:33751418654
VL - 141
SP - 122
EP - 126
JO - Solid State Communications
JF - Solid State Communications
SN - 0038-1098
IS - 3
ER -