arXiv subjects

Bin-Bin Ruan

Publications and source records attributed to Bin-Bin Ruan.

21 records · Page 2Linked to original sources

arXiv2016

Superconductivity in undoped CaFe2As2 single crystals

Single crystals of undoped CaFe2As2 were grown by a FeAs self-flux method, and the crystals were quenched in ice-water rapidly after high temperature growth. The quenched crystal undergoes a collapsed tetragonal structural phase transition around 80 K revealed by the temperature dependent X-ray diffraction measurements. Superconductivity below 25 K was observed in the collapsed phase by resistivity and magnetization measurements. The isothermal magnetization curve measured at 2 K indicates that this is a typical type-II superconductor. For comparison, we systematically characterized the properties of the furnace cooled, quenched, and post-annealed single crystals, and found strong internal crystallographic strain existing in the quenched samples, which is the key for the occurrence of superconductivity in the undoped CaFe2As2 single crystals.

cond-mat.supr-con↗

arXiv2015

Superconductivity at 3.85 K in BaPd2As2 with the ThCr2Si2-type structure

The single crystal of ThCr2Si2-type BaPd2As2 was successfully prepared by a self-flux method, and the crystal structure was characterized by X-ray diffraction method with the lattice parameters a = 4.489(2) Å and c = 10.322(3) Å. Bulk superconductivity below a Tc (critical temperature) of 3.85 K was revealed in this compound by the measurements of resistivity, magnetic susceptibility and specific heat, and this Tc is much higher than those of other isostructural Pd-based superconductors.

cond-mat.supr-con↗

arXiv2014

Enhanced superconductivity in F-doped LaO1-xFxBiSSe

The layered compound LaOBiSSe was successfully synthesized by a two-step solid-state reaction method, which is isostructural with the quaternary compound LaOBiS2 indicated by the powder X-ray diffraction characterization, and the crystal lattice parameters are slightly expanded by the substitution of Se atoms. Electrical transport measurement shows that LaOBiSSe exhibits semiconducting behavior similar with the parent compound LaOBiS2, while by F-doping the samples can be much more easily turned to be metallic and superconducting at low temperature with a small amount of F. Under the optimal carrier doping concentration of F ~ 0.5, the superconducting critical temperature of LaO0.5F0.5BiSSe is clearly enhanced up to a value of 3.8 K than the 3.2 K of LaO0.5F0.5BiS2.

cond-mat.supr-con↗