In this article,the Sm-doping single crystals Ca1-xSmxFe2As2(x = 0 0.2) were prepared by the Ca As flux method,and followed by a rapid quenching treatment after the high temperature growth.The samples were characterized by structural,resistive,and magnetic measurements.The successful Sm-substitution was revealed by the reduction of the lattice parameter c,due to the smaller ionic radius of Sm3+than Ca2+.Superconductivity was observed in all samples with onset Tc varying from 27 K to 44 K upon Sm-doping.The coexistence of a collapsed phase transition and the superconducting transition was found for the lower Sm-doping samples.Zero resistivity and substantial superconducting volume fraction only happen in higher Sm-doping crystals with the nominal x > 0.10.The doping dependences of the c-axis length and onset Tc were summarized.The high-Tc observed in these quenched crystals may be attributed to simultaneous tuning of electron carriers doping and strain effect caused by lattice reduction of Sm-substitution.
In this article,the Sm-doping single crystals Ca1-xSmxFe2As2(x = 0 0.2) were prepared by the Ca As flux method,and followed by a rapid quenching treatment after the high temperature growth.The samples were characterized by structural,resistive,and magnetic measurements.The successful Sm-substitution was revealed by the reduction of the lattice parameter c,due to the smaller ionic radius of Sm3+than Ca2+.Superconductivity was observed in all samples with onset Tc varying from 27 K to 44 K upon Sm-doping.The coexistence of a collapsed phase transition and the superconducting transition was found for the lower Sm-doping samples.Zero resistivity and substantial superconducting volume fraction only happen in higher Sm-doping crystals with the nominal x 〉 0.10.The doping dependences of the c-axis length and onset Tc were summarized.The high-Tc observed in these quenched crystals may be attributed to simultaneous tuning of electron carriers doping and strain effect caused by lattice reduction of Sm-substitution.