Superconductivity in Sm-doped CaFe2As2 single crystals

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.

Giant piezoelectricity of Sm-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals

The Sm-doped Pb(Mg1/3Nb2/3)O3-PbTiO3(Sm-PMN-PT)single crystals were successfully grown and systematically investigated with the support of the National Natural Science Foundation of China.The research team is led by Prof.Li Fei(李飞)at the Electronic Materials Research Laboratory,School of Electronic and Information Engineering,Xi'an Jiaotong University,and with collaboration of The Pennsylvania State University,University of Wollongong,University of South Carolina,University of Arkansas,etc.This work was published in Science(2019,364:264—268).

Sm-doped g-C_(3)N_(4)/Ti_(3)C_(2) MXene heterojunction for visible-light photocatalytic degradation of ciprofloxacin

A heterojunction of Sm-doped g-C_(3)N_(4)/Ti_(3)C_(2) MXene(SCN/MX)was constructed via prepolymerization and solid mixture-calcination method.The modified g-C_(3)N_(4) presented a hollow porous seaweed-like shape which can increase its specific area and active sites.In SCN/MX composite,the optical properties,no matter optical absorption ability or separation performance of photo-induced electrons and holes,were enhanced.Among them,Sm-doping may play an important role on transferring the photogenerated electrons to suppress their recombination,and Ti_(3)C_(2) MXene would broaden light absorption and further improve the carrier migration efficiency.The SCN/MX presented higher photocatalytic degradation efficiency(>99%)of cipro floxacin under visible light irradiation.The quenching experiments and electron spin-resonance spectroscopy confirmed that the dominated active materials were superoxide radical and holes.The degradation mechanisms of ciprofloxacin(CIP)over the SCN/MX were attacking of the active materials on the piperazine ring and quinolone ring,and the final products were CO_(2),H_(2)O and F^(-).

Enhanced visible-light photocatalytic activity of samarium-doped zinc oxide nanostructures

In the present work,we have synthesized samarium doped zinc oxide nanostructures(Zn1-xSmxO;x=0.00,0.02,0.04 and 0.06) via chemical precipitation method and studied their structural,morphological,optical and photocatalytic properties.X-ray diffraction(XRD) patterns,PL and Raman spectra results indicate that the undoped and Sm-doped ZnO nanostructures are crystallized in a hexagonal wurtzite structure.FESEM images show that the morphology of the sample changes from cubical to hexagonal nanostructures with increase in Sm3+doping concentration.The EDX spectra confirm the incorporation of Sm3+ion in ZnO.The influence of Sm3+doping on the structure,morphology,absorption,emission and photocatalytic activity of ZnO nanostructures were investigated systematically.The addition of Sm3+ion leads to a red shift in the optical energy band gap from 3.19 to 2.67 eV and hence,increases the visible light absorption ability.The presence of E2(H) and E1(LO) modes in microRaman spectra confirms the crystallinity and defects in the samples.The detailed photocatalytic experiments reveal that Sm-doped ZnO nanostructures show the maximum photodegradation efficiency for Methylene blue(MB) dye for x=0.04,i,e.,94.94%,under visible light irradiation.The photocatalytic efficiency improves by 6.98 times when ZnO is doped with rare earth metal ion(Sm3+) and is a potential candidate for practical applications.The investigation demonstrates that as-synthesized nano-sized photocatalysts act as an efficient photocatalyst for the degradation of MB dye.