Single-crystal growth of Mg- and Ni-doped chain compound SrCuO2 by the traveling-solvent floating-zone method and chain breaking effect induced by the dopants

Effect of different in-chain impurities on the magnetic properties of the spin chain compound SrCuO2 probed by NMR

“…The samples were prepared using the traveling solvent floating zone (TSFZ) method using starting materials of at least 99.99 % purity. [36][37][38][39] The high quality of the crystals has been checked by x-ray diffraction (phase determination) and energy-dispersive x-ray spectroscopy (chemical composition) measurements. After determining the orientation with a Laue camera, preferably cubic shaped pieces were cut out of the crystals to have samples with the edges aligned along the crystallographic axes.…”

Magnetic ordering in the ultrapure site-diluted spin chain materialsSrCu1−xNixO2

“…30 For pure and Ni-doped SrCuO 2 single crystal growth, feed rods with 0.0, 0.1, 0.25, 0.5 and 1 % of Ni doping concentrations were prepared using SrCO 3 (99.99% or 99.9995%, Alfa Aesar), CuO (99.99% or 99.9995%, Chempur) and NiO (99.99%, Alfa Aesar) powders. The powders were ground and sintered several times at 900-990…”

“…Single crystals of SrCu 1−x Ni x O 2 were grown using the floating zone method. 30 For pure and Ni-doped SrCuO 2 single crystal growth, feed rods with 0.0, 0.1, 0.25, 0.5 and 1 % of Ni doping concentrations were prepared using SrCO 3 (99.99% or 99.9995%, Alfa Aesar), CuO (99.99% or 99.9995%, Chempur) and NiO (99.99%, Alfa Aesar) powders. The powders were ground and sintered several times at 900-990 • C and shaped in a rubber tube (diameter = 6 mm, length = 80 mm) at a pressure of 2500 bar.…”

“…Their lattice constants, obtained by the Rietveld analysis, does not change significantly in our doping region. 30 The magnetic susceptibility measurements were performed on the same crystals that were used in the following muon experiments. The crystals were aligned with the c crystal axis parallel to the applied magnetic field.…”

“…16,27,28 The advantage is that the techniques for precisely controlling Ni 2+ substitution and ensuring exceptional sample purity in SrCuO 2 have been very well established in the course of recent transport studies. 17,18,24,29,30 Below we report on a series of µSR experiments on this type of ultrapure samples. From these experiments, we draw several important conclusions regarding long-range order in the parent compound and in the Ni-diluted derivatives: i) contrary to previous reports of glassy behavior, 21 magnetic order in stoichiometric SrCuO 2 is a conventional, entirely homogeneous state; ii) A Ni concentration of as little as 0.5% almost entirely suppresses static magnetic order and iii) the concentration dependence of T N for low impurity levels is in good agreement with the theoretical predictions of Ref.…”