Superconducting Properties and Phase Diagram of Indirectly Electron-Doped $(\hbox{Sr}_{1 - x}\hbox{La}_{x})\hbox{Fe}_{2}\hbox{As}_{2}$ Epitaxial Films Grown by Pulsed Laser Deposition

A nonequilibrium phase (Sr<sub>1-x</sub>La<sub>x</sub>)Fe<sub>2</sub>As<sub>2</sub> was formed by epitaxial film-growth. The resulting films emerged superconductivity along with suppression of the resistivity anomaly, which is associated with magnetic and structural phase transitions. The maximum critical temperature was 20.8 K, which is almost the same as that of directly electron-doped Sr(Fe<sub>1-x</sub>Co<sub>x</sub>)<sub>2</sub>As<sub>2</sub>. Its electronic phase diagram is much similar to that of Sr( Fe<sub>1-x</sub>Co<sub>x</sub>)<sub>2</sub>As<sub>2</sub>, indicating that the difference in the electron doping sites does not influence the superconducting properties of 122-type SrFe<sub>2</sub>As<sub>2</sub>.

[1]  T. Kamiya,et al.  Thin film growth by pulsed laser deposition and properties of 122-type iron-based superconductor AE(Fe1−xCox)2As2 (AE=alkaline earth) , 2012, 1205.4103.

[2]  T. Kamiya,et al.  Thin Film Growth and Device Fabrication of Iron-Based Superconductors , 2011, 1111.0358.

[3]  T. Kamiya,et al.  Identical effects of indirect and direct electron doping of superconducting BaFe 2 As 2 thin films , 2011, 1110.0045.

[4]  Chengduo Wang,et al.  Transport properties and anisotropy in rare-earth doped CaFe2As2 single crystals with Tc above 40 K , 2011, 1106.4208.

[5]  Yanyi Sun,et al.  Unusual superconducting state at 49 K in electron-doped CaFe2As2 at ambient pressure , 2011, Proceedings of the National Academy of Sciences.

[6]  P. Zavalij,et al.  Structural collapse and superconductivity in rare-earth-doped CaFe2As2 , 2011, 1105.4798.

[7]  H. Hosono,et al.  Hydrogen in layered iron arsenides: Indirect electron doping to induce superconductivity , 2011, 1103.1177.

[8]  H. Hosono,et al.  High Pressure Synthesis of Indirectly electron-doped 122 Iron Superconductor Sr1-xLaxFe2As2 with a maximum Tc = 22 K , 2010, 1005.0528.

[9]  L. Schultz,et al.  Scaling behaviour of the critical current in clean epitaxial Ba(Fe1-xCox)2As2 thin films , 2010, 1001.2505.

[10]  H. Hosono,et al.  Angular and field properties of the critical current and melting line of Co-doped SrFe2As2 epitaxial films , 2009 .

[11]  Dong Ho Kim,et al.  In-situ fabrication of cobalt-doped SrFe2As2 thin films by using pulsed laser deposition with excimer laser , 2009, 0907.4227.

[12]  H. Kontani,et al.  Violation of Anderson's Theorem for Sign-Reversing s-wave Superconducting State in Iron Pnictides , 2009 .

[13]  R. Arita,et al.  Three-Dimensional Electronic Structure of Superconducting Iron Pnictides Observed by Angle-Resolved Photoemission Spectroscopy , 2009, 0906.1846.

[14]  David J. Singh,et al.  Evidence for three-dimensional Fermi-surface topology of the layered electron-doped iron superconductor Ba(Fe 1-x Co x ) 2 As 2 , 2009 .

[15]  T. Kamiya,et al.  Heteroepitaxial film growth of layered compounds with the ZrCuSiAs-type and ThCr2Si2-type structures: From Cu-based semiconductors to Fe-based superconductors , 2009 .

[16]  T. Kamiya,et al.  Water-induced superconductivity in SrFe 2 As 2 , 2009, 0903.3710.

[17]  Yang Wang,et al.  Effects of cobalt doping and phase diagrams of LFe1-xCox AsO (L=La and Sm) , 2009 .

[18]  H. Hosono,et al.  Pseudoisotropic upper critical field in cobalt-doped SrFe2As2 epitaxial films. , 2008, Physical review letters.

[19]  D. Christen,et al.  Small anisotropy, weak thermal fluctuations, and high field superconductivity in Co-doped iron pnictide Ba(Fe1-xCox)2As2 , 2008, 0810.0699.

[20]  T. Kamiya,et al.  Superconductivity in Epitaxial Thin Films of Co-Doped SrFe2As2 with Bilayered FeAs Structures and their Magnetic Anisotropy , 2008, 0808.1985.

[21]  A. Leithe-Jasper,et al.  Superconducting state in SrFe2-xCoxAs2 by internal doping of the iron arsenide layers. , 2008, Physical review letters.

[22]  F. Schappacher,et al.  Structural and magnetic phase transitions in the ternary iron arsenides SrFe2As2 and EuFe2As2 , 2008, 0806.4782.

[23]  Liling Sun,et al.  Superconductivity at 55 K in Iron-Based F-Doped Layered Quaternary Compound Sm[O1-xFx] FeAs , 2008 .

[24]  Marcus Tegel,et al.  Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2. , 2008, Physical review letters.

[25]  Hideo Hosono,et al.  Iron-based layered superconductor La[O(1-x)F(x)]FeAs (x = 0.05-0.12) with T(c) = 26 K. , 2008, Journal of the American Chemical Society.

[26]  E. Helfand,et al.  Temperature and Purity Dependence of the Superconducting Critical Field, H c 2 . III. Electron Spin and Spin-Orbit Effects , 1966 .

[27]  N. R. Werthamer,et al.  Nonlinear self-coupling of Josephson radiation in superconducting tunnel junctions , 1966 .

[28]  E. Helfand,et al.  Temperature and purity dependence of the superconducting critical field, H/sub c2/ , 1964 .

[29]  周放,et al.  Superconductivity at 55 K in Iron-Based F-Doped Layered Quaternary Compound Sm[O1-xFx]FeAs , 2008 .