Superconductivity in Undoped CaFe2As2 Single Crystals

Single crystals of undoped CaFe2As2 are grown by an FeAs self-flux method, and the crystals are 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 diffr...

Full description

Saved in:
Bibliographic Details
Published in中国物理快报：英文版 no. 6; pp. 128 - 131
Main Author 陈东云 于佳 阮彬彬 郭琦 张蕾 陈根富 任治安
Format Journal Article
LanguageEnglish
Published 01.06.2016
Subjects
单晶体
快速淬火
掺杂
温度依赖性
磁化强度
结构相变
衍射测量
超导电性
Online AccessGet full text
ISSN0256-307X
1741-3540
DOI10.1088/0256-307X/33/6/067402

Cover

More Information
Summary:Single crystals of undoped CaFe2As2 are grown by an FeAs self-flux method, and the crystals are 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 is 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-ll superconductor. For comparison, we systematically characterize the properties of the furnace-cooled, quenched, and post-annealed single crystals, and find strong internal crystallographic strain existing in the quenched samples, which is the key for the occurrence of superconductivity in the undoped CaFe2As2 single crystals.
Bibliography:11-1959/O4
Single crystals of undoped CaFe2As2 are grown by an FeAs self-flux method, and the crystals are 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 is 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-ll superconductor. For comparison, we systematically characterize the properties of the furnace-cooled, quenched, and post-annealed single crystals, and find strong internal crystallographic strain existing in the quenched samples, which is the key for the occurrence of superconductivity in the undoped CaFe2As2 single crystals.
ISSN:0256-307X
1741-3540
DOI:10.1088/0256-307X/33/6/067402