CRYSTAL-GROWTH OF LA(2-X)SR(X)CUO(4-DELTA) BY THE TRAVELING-SOLVENT FLOATING-ZONE METHOD

The crystal-growth conditions for La(2-x)Sr(x)CuO4-delta by the travelling-solvent floating-zone method have been investigated. The effect of the ambient atmosphere on the growth has been studied. Results show that evaporation of components from the floating zone is very low and does not significantly influence the growth procedure. However, high oxygen ambient pressure can lead to formation of second phases like LaCuO3. The composition and amount of solvent were also investigated. It is shown that the denstiy and porosity of the starting feed material are the crucial variables for a successful growth procedure. The ''twice-scanning'' method has been chosen to achieve stable growing processes at low growth rate. The characterization of as-grown crystals by DC susceptibility, rocking X-ray curve and electron-probe microanalysis (EPMA) measurement is reported.