Binary cuprates of Sr2CuO3+δ and SrCuO2 have been synthesized at low temperatures below 500°C under various values of partial oxygen-pressure PO2 by thermal decomposition of hydroxide precursors, Sr2Cu(OH)6 and SrCu(OH)4, respectively. The tetragonal Sr2CuO3+δ (δ ∼ 0.3) is obtained by the heat-treatment at 400°C and PO2 ≥ 0.2 atm. The value of δ appears to be independent of PO2 and unchangeable. On the other hand, the orthorhombic Sr2CuO3+δ (δ ∼ 0) is obtained by the heat-treatment at 400°C in flowing gas of N2. For 0 < PO2 < 0.2 atm, a mixture of the tetragonal and orthorhombic phases is obtained. The orthorhombic SrCuO2 is obtained by the heat-treatment at 500°C in flowing gas of N2, although the tetragonal SrCuO2, namely, the so-called infinite-layer compound is not obtained.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Condensed Matter Physics