High oxygen pressure single crystal growth of highly Ca-doped spin ladder compound Sr14−xCaxCu24O41 (x>12)

Abstract

a b s t r a c tLarge size high-quality Ca-doped Sr 14 À x Ca x Cu 24 O 41 (x ¼ 12.2, 12.6 and 13) spin ladder superconducting single crystals were grown using a modified mirror floating zone furnace with oxygen pressure up to 35 bar. The qualities of the as-grown single crystals were confirmed by polarized optical microscopy, neutron diffraction and X-ray diffraction methods. The sample compositions and homogeneity were measured using micro-X-ray fluorescence spectroscopy. The lattice parameters of each sample have been refined using the Rietveld method. The oxygen stoichiometry measurements which were performed by hydrogen reduction/thermogravimetry method show that all the three samples are slightly oxygen deficient even though high oxygen pressure was applied during growth. The high oxygen pressure is indispensible for growing highly Ca-doped Sr 14 À x Ca x Cu 24 O 41 single crystals. The susceptibility was measured along c-axis for all three compositions, fitting well with the one dimensional dimer model, consistent with the reported values of undoped Sr 14 Cu 24 O 41 parent compounds.

Coexistence of long-range magnetic ordering and singlet ground state in the spin-ladder superconductor SrCa13Cu24O41<

“…A SrCa13 single crystal was grown by using a traveling solvent-floating zone technique with 35 Bar high oxygen pressure. 18 High resolution x-ray powder diffraction experiments with the powderized samples from different parts of the crystal boule were carried out on a Bruker D8 x-ray diffractometer, confirming the phase purity of the as-grown single crystal. 18 The magnetic susceptibility was measured using a superconducting quantum interference device (SQUID) magnetometer (Cryogenic Ltd.).…”

Spin-gap evolution upon Ca doping in the spin-ladder series Sr14−xCaxCu24

“…The crystal growth procedure was described in detail in Ref. 11. The inelastic neutron scattering experiments were carried out on the triple axis spectrometer 1T1 at the Orphée reactor, Laboratoire Léon Brillouin (LLB) and TAIPAN at the Open Pool Australian Lightwater (OPAL) reactor, ANSTO.…”

Floating zone crystal growth and magnetic properties of bilayer manganites Pr(Sr1−xCax)2Mn2O7

“…It is worthwhile to mention that highly Ca-doped spin ladder Sr 14-x Ca x Cu 24 O 41 could also be grown only at high oxygen pressure. We have successfully grown single crystals of Sr 1 Ca 13 Cu 24 O 41 with a modified image furnace applying 35 bar of oxygen pressure [8]. Both cases hint that oxygen pressure is an essential factor for synthesis of certain transition metal oxides even when their tolerance factors are unfavorable.…”