2008/06/09 by G. Wu, R. H. Liu, H. Chen +7 · 1 citation
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Magnetic and transport properties of perovskites and related materials #Superconductivity in MgB2 and Alloys #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1209/0295-5075/84/27010
published as Europhysics Letters 84, 27010(2008). · 4 pages, 4 figures
arxiv created 2008/06/09 · openalex publication_date 2008/10/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We synthesized the samples Ba 1- x M x Fe 2 As 2 (M=La and K) with a ThCr 2 Si 2 -type structure. These samples were systematically characterized by resistivity, thermoelectric power (TEP) and Hall coefficient ( R H ). BaFe 2 As 2 shows an anomaly in resistivity at about 140 K. The substitution of La for Ba leads to a shift of the anomaly to low temperature, but no superconducting transition is observed. Potassium doping leads to the suppression of the anomaly in resistivity and induces superconductivity at 38 K. The Hall coefficient and TEP measurements indicate that the TEP is negative for BaFe 2 As 2 and La-doped BaFe 2 As 2 , indicating an n -type carrier; while potassium doping leads to a change of the sign in R H and TEP. It definitely indicates a p -type carrier in the superconducting Ba 1- x K x Fe 2 As 2 with double FeAs layers, being in contrast to the case of LnO 1- x F x FeAs with a single FeAs layer.