Sr_<0.09>Ca_<0.91>CuO_2の合成と結晶構造

概要

論文の詳細を見る
Sr_<0.09>Ca_<0.91>CuO_2 was obtained by heating a powder mixture of SrCO_3, CaCO_3, and CuO at 1000℃ in flowing oxygen. The compound has a tetragonal symmetry, P4/mmm, and is characterized by a=3.8581 (1), c=3.1997(1)A^^゜, Z=1, D_m= 4.86 g/cm^3, and D_<cal>=4.88 g/cm^3 The crystal structure was determined and refined to R_ρ= 3.7% by the Rietveld analysis of X- ray powder diffraction data. The compound has an oxygen-deficient perovskite structure. A copper atom is in a square plane of oxygen atoms. This square plane forms a Cu- O flat sheet sharing the oxygen atoms at vertices of the square. The bond length of Cu- O is 1.929 A^^゜. Sr(0.09) and Ca(0.91 ) atoms are statistically in an oxygen square prism. The interatomic distance of ( Ca, Sr) - O is 2.506 A^^゜. This compound is a p-type semiconductor with electric conductivity of 1.2X10^<-4> (Ω・cm)^<-1> at 22℃.
社団法人日本セラミックス協会の論文
1989-02-01