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arXiv · 1401.0097

La-substituted CaFeAsH superconductor with Tc = 47 K

Yoshinori Muraba·Satoru Matsuishi·Hideo Hosono
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Abstract

La-substituted CaFeAsH,(Ca1-xLax)FeAsH, were synthesized by the solid state reaction at 1173 K under high pressure of 2.5 GPa. The r-T anomaly corresponding to tetragonal to orthorhombic structural transition was suppressed by La-substitution and then the superconductivity was observed at an electron doping content of Ne > 0.05. The maximum onset Tc of 47.4 K was reached for Ne = 0.18, which is significant increase compared to 23 K achieved by direct electron doping to the FeAs-layer via Co-substitution to the Fe-site. This value of Tc value fits well to the phenomenological relation between Tc and the bond angle of As-Fe-As in indirectly electron doped LnFeAsO (Ln = Lanthanide). These results indicate that the electron was doped via the indirect mode through the aliovalent ion substitution to CaH-layer (Ca2+ La3+ + e-).

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Yoshinori Muraba, Satoru Matsuishi, Hideo Hosono. 2013-12-31. La-substituted CaFeAsH superconductor with Tc = 47 K. https://doi.org/10.7566/jpsj.83.033705

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