TY - JOUR
T1 - On the excess oxygen in four-layered rock-salt-type units of modulated thermoelectric Bi-Sr-(Co,Rh)-O compounds
AU - Yubuta, Kunio
AU - Miyazaki, Yuzuru
AU - Terasaki, Ichiro
AU - Kajitani, Tsuyoshi
N1 - Funding Information:
This study was partly supported by the Core Research for Evolution Science and Technology (CREST) Project of Japan Science and Technology Agency (JST) and also by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.
PY - 2009/7
Y1 - 2009/7
N2 - Excess oxygen exists in four-layered rock-salt (RS)-type units of modulated misfit-layered Bi-Sr-(Co,Rh)-O compounds, which consist of interpenetrating CdI 2-type (Co,Rh)O 2 and distorted four-layered RS-type block subsystems, which have two b-axes, i.e., b 1 and b 2, respectively. From carefully determined chemical contents and misfit ratios, p = b 1/b 2, two structural characteristics are concluded, namely, intermixing metal ions in the RS-type layers and excess oxygen δ in, or in the vicinity of, them. The chemical formulae are proposed as [(Bi 1-x (Co,Rh) x ) 2(Sr 1-y Bi y ) 2O 4+δ ] p (Co,Rh)O 2. The valence states of?cobalt and rhodium ions are close to 3.3+. These valence states are quite reasonable for good thermoelectric oxides, such as γ-Na 0.7CoO 2 and [Ca 2CoO 3] 0.62CoO 2. Excess oxygen would cause the undulated atomic arrangement.
AB - Excess oxygen exists in four-layered rock-salt (RS)-type units of modulated misfit-layered Bi-Sr-(Co,Rh)-O compounds, which consist of interpenetrating CdI 2-type (Co,Rh)O 2 and distorted four-layered RS-type block subsystems, which have two b-axes, i.e., b 1 and b 2, respectively. From carefully determined chemical contents and misfit ratios, p = b 1/b 2, two structural characteristics are concluded, namely, intermixing metal ions in the RS-type layers and excess oxygen δ in, or in the vicinity of, them. The chemical formulae are proposed as [(Bi 1-x (Co,Rh) x ) 2(Sr 1-y Bi y ) 2O 4+δ ] p (Co,Rh)O 2. The valence states of?cobalt and rhodium ions are close to 3.3+. These valence states are quite reasonable for good thermoelectric oxides, such as γ-Na 0.7CoO 2 and [Ca 2CoO 3] 0.62CoO 2. Excess oxygen would cause the undulated atomic arrangement.
KW - Chemical composition
KW - Electron diffraction
KW - High-resolution electron microscopy image
KW - Misfit-layered structure
KW - Valence state
UR - http://www.scopus.com/inward/record.url?scp=67650488229&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67650488229&partnerID=8YFLogxK
U2 - 10.1007/s11664-009-0705-7
DO - 10.1007/s11664-009-0705-7
M3 - Article
AN - SCOPUS:67650488229
VL - 38
SP - 1116
EP - 1120
JO - Journal of Electronic Materials
JF - Journal of Electronic Materials
SN - 0361-5235
IS - 7
ER -