ChemInform Abstract: PREPARATION AND STUDY OF THE α AND β PHASES OF LITHIUM COBALT OXIDE (LI1.5+XCO1.5‐XO3) (O ≤ X ≤ 0.35)

Abstract

Bei längerem Erhitzen eines Co3O4‐Li2O‐Gemischs auf 600‐850°C unter Sauerstoffdruck bildet sich eine rhomboedrische Phase mit der im Titel angegebenen Zusammensetzung (et‐Phase).

Defect Chemistry of " BaCuO2" I. Oxygen Non -Stoichiometry, Cation Molecularity and X-ray Diffraction Determinations

“…Conversely, the reproducible behavior of the 88:90 composition is a further argument in favor of its monophasic nature, which adds to the conclusions of the previous section. Along the same line of argu ments, the different Ba:Cu ratio is a reasonable expla nation of the disagreement with previous non-stoichiometry data from Migeon et al [4,11].…”

“…The same Authors also gave an unindexed list of poweder X-ray diffraction lines and a preliminary characterization of its mag netic properties. According to the electron diffraction determinations of Migeon et al [4], the crystal struc ture belongs to one of the space groups Im3m, I43m or 1432, the cubic unit cell is ~ 1.826 nm wide, and con tains ~90 (BaCu02) formula units. The following pa pers were in agreement with these data as well as with the indexed diffraction pattern given by the latter Au thors.…”

“…After the first work by Arjomand and Machin [3], "BaCuO2" has been investigated as to space group symmetry [4], crystal structure determination from single crystal and powder Rietveld methods [5][6][7][8][9][10], oxygen non-stoichiometry and cation molecularity [9][10][11][12][13][14][15], thermodynamic data [15,16], Raman spec troscopy [17], electrical conductivity [4,11], thermopower [4,11], and magnetic and ferroelectric behavior [4,11,18]. Crystallography and crystal chemistry of Reprint requests to Prof. G. Spinolo. the various compounds in the whole Ba, Cu/O system have been recently reviewed by Wong-Ng and Cook [19].…”

Magnetization studies of oxides related to the high temperature cuprate superconductors

“…The lattice parameter was found to be ao = 18.29 ± 0.03 A for the He-annealed sample, and ao = 18.34 ± 0.03 A for the oxygen-annealed sample. The lattice parameter thus appears to increase as the oxygen content increases, as also observed by Weller (18.277 -18.286 A) [61], .31 A) [68], and .32 A) [64] [65]. Our oxygen-and helium-annealed samples were found [66] from neutron difTraction measurements to have essentially the same structure as proposed in [60] and [61].…”

The identification of two superconducting phases in the Tl-Ba-Ca-Cu oxide system

“…Several unindexed diffraction peaks in the trace are found to be from impurities. Note that diffraction peaks for the BaCuO [8] compound almost overlap with some of those from the 120 K superconductor; this might cause confusion in counting diffraction intensities for structure determination. Our results are consistent with those of other electron diffraction studies [S].…”