Department of Physics, ‡State Key Lab of Silicon Materials, and §Center of Electron Microscope, Zhejiang University , Hangzhou 310027, China.
J Am Chem Soc. 2012 Aug 8;134(31):12893-6. doi: 10.1021/ja304315e. Epub 2012 Jul 26.
We have synthesized a new oxypnictide, Ba2Ti2Fe2As4O, via a solid-state reaction under a vacuum. The compound crystallizes in a body-centered tetragonal lattice, which can be viewed as an intergrowth of BaFe2As2 and BaTi2As2O, thus containing Fe2As2 layers and Ti2O sheets. Bulk superconductivity at 21 K is observed after annealing the as-prepared sample at 773 K for 40 h. In addition, an anomaly in resistivity and magnetic susceptibility around 125 K is revealed, suggesting a charge- or spin-density wave transition in the Ti sublattice.
我们通过真空固态反应合成了一种新的氧磷化物 Ba2Ti2Fe2As4O。该化合物在体心四方晶格中结晶，可视为 BaFe2As2 和 BaTi2As2O 的混合体，因此含有 Fe2As2 层和 Ti2O 片。对未经退火的样品在 773 K 下退火 40 h 后，观察到 21 K 的体超导电性。此外，在 125 K 左右的电阻率和磁化率出现异常，表明 Ti 亚晶格中存在电荷或自旋密度波跃迁。
