The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagne...The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagnetic or structural transition is suppressed with Sb content, and a high-To superconducting phase, accompanied by a low-Tc phase, emerges at 0.02 ≤y ≤ 0.06. In this intermediate-doping regime, normal-state transport shows non-Fermi-liquid-like behaviors with nearly T-linear resistivity above the high-Tc phase. With further Sb doping, this high-Tc phase abruptly vanishes for y 〉 0.06 and the conventional Fermi liquid is restored, while the low-T,, phase remains robust against Sb inlpurities. The coincidence of the high-Tc phase and non-Fermi liquid transport behaviors in the intermediate Sb-doping regime suggests that AFM fluctuations play an important role in the observed non-Fermi liquid behaviors, which may be intimately related to the unusual nonbulk high-Tc phase in this system.展开更多
Mossbauer spectrum measured for the iron components of photosystem Ⅱ (PS Ⅱ ) particles of spinach is a superposition of 4 doublets. Quadrupole splitting and chemical shifting of doublets I -IV are characteris-tics o...Mossbauer spectrum measured for the iron components of photosystem Ⅱ (PS Ⅱ ) particles of spinach is a superposition of 4 doublets. Quadrupole splitting and chemical shifting of doublets I -IV are characteris-tics of proteins with oxidized cytochrome b-559, reduced cytochrome b-559, Fe3 + -Q complex and Fe2+ -Q complex re-spectively . After the PS II particles are treated with La3+ , two doublets of Fe2+ disappear and Fe2+ is converted into Fe3+ , indicating that the reduced cytochrome b-559 has been converted into the oxidized cytochrome b-559, and Fe2+-Q complex into Fe3+-Q complex. The Mossbauer spectrum of PS II particles treated with La3+ and Ca2+ shows that Ca2+ can weaken the inhibitory effect of La3+ in part, and a portion of the reduced cytochrome b-559 and Fe-Q complex still exist.展开更多
基金This work was supported by tile National Natural Science Foundation of China （Grant Nos. U1432135, 11674054, 11474080, and 11611140101） and the Scientific Research Foundation of Graduate School of Southeast University （Grant No. YBJJ1621）. X. Xu would also like to acknowledge the National Key Basic Research Program of China （Grant No. 2014CB648400） and the support from the Distinguished Young Scientist Funds of Zhejiang Province （No. LR14A040001）.
文摘The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagnetic or structural transition is suppressed with Sb content, and a high-To superconducting phase, accompanied by a low-Tc phase, emerges at 0.02 ≤y ≤ 0.06. In this intermediate-doping regime, normal-state transport shows non-Fermi-liquid-like behaviors with nearly T-linear resistivity above the high-Tc phase. With further Sb doping, this high-Tc phase abruptly vanishes for y 〉 0.06 and the conventional Fermi liquid is restored, while the low-T,, phase remains robust against Sb inlpurities. The coincidence of the high-Tc phase and non-Fermi liquid transport behaviors in the intermediate Sb-doping regime suggests that AFM fluctuations play an important role in the observed non-Fermi liquid behaviors, which may be intimately related to the unusual nonbulk high-Tc phase in this system.
基金Project supported by the National Natural Science Foundation of China and the Natural Science Foundation of the Chinese Educational Commission.
文摘Mossbauer spectrum measured for the iron components of photosystem Ⅱ (PS Ⅱ ) particles of spinach is a superposition of 4 doublets. Quadrupole splitting and chemical shifting of doublets I -IV are characteris-tics of proteins with oxidized cytochrome b-559, reduced cytochrome b-559, Fe3 + -Q complex and Fe2+ -Q complex re-spectively . After the PS II particles are treated with La3+ , two doublets of Fe2+ disappear and Fe2+ is converted into Fe3+ , indicating that the reduced cytochrome b-559 has been converted into the oxidized cytochrome b-559, and Fe2+-Q complex into Fe3+-Q complex. The Mossbauer spectrum of PS II particles treated with La3+ and Ca2+ shows that Ca2+ can weaken the inhibitory effect of La3+ in part, and a portion of the reduced cytochrome b-559 and Fe-Q complex still exist.
