The discovery of cuprate high TC superconductors has inspired the search for unconventional superconductors in magnetic materials.A successful recipe has been to suppress long−range order in a magnetic parent compound...The discovery of cuprate high TC superconductors has inspired the search for unconventional superconductors in magnetic materials.A successful recipe has been to suppress long−range order in a magnetic parent compound by doping or high pressure to drive the material towards a quantum critical point.We report an exception to this rule in the recently discovered potassium iron selenide.The superconducting composition is identified as the iron vacancy ordered K_(0.83)(2)Fe_(1.64)(1)Se_(2) with T_(C) above 30 K.A novel large moment 3.31μB/Fe antiferromagnetic order that conforms to the tetragonal crystal symmetry has an unprecedentedly high ordering temperature TN≈559 K for a bulk superconductor.Staggeringly polarized electronic density of states is thus suspected,which would stimulate further investigation into superconductivity in a strong spin-exchange field under new circumstances.展开更多
Under hydrothermal conditions, the reactions of NiII/CuII ions with 3-（6-aminpyri- dinium-3-yl） benzoate （HL） afford two compounds [NiL2]n （1） and [CuL2（H2O）]n （2）. On the basis of X-ray diffraction analysis...Under hydrothermal conditions, the reactions of NiII/CuII ions with 3-（6-aminpyri- dinium-3-yl） benzoate （HL） afford two compounds [NiL2]n （1） and [CuL2（H2O）]n （2）. On the basis of X-ray diffraction analysis of the two compounds, the results show that compound 1 features one-dimensional （1D） double-strand coordination arrays, while 2 presents the 63-hcb layers. Both compounds are further constructed into a 3D supramolecular structure with the aid of weak secondary interactions. Thermal stabilities and magnetic properties of compounds 1 and 2 were also investigated.展开更多
基金by the National Natural Science Foundation of China under Grant Nos 11034012,10834013 and 10974254the National Basic Research Program of China under Grant Nos 2011CBA00112,2010CB923000 and 2009CB009100.
文摘The discovery of cuprate high TC superconductors has inspired the search for unconventional superconductors in magnetic materials.A successful recipe has been to suppress long−range order in a magnetic parent compound by doping or high pressure to drive the material towards a quantum critical point.We report an exception to this rule in the recently discovered potassium iron selenide.The superconducting composition is identified as the iron vacancy ordered K_(0.83)(2)Fe_(1.64)(1)Se_(2) with T_(C) above 30 K.A novel large moment 3.31μB/Fe antiferromagnetic order that conforms to the tetragonal crystal symmetry has an unprecedentedly high ordering temperature TN≈559 K for a bulk superconductor.Staggeringly polarized electronic density of states is thus suspected,which would stimulate further investigation into superconductivity in a strong spin-exchange field under new circumstances.
基金supported by the National Natural Science Foundation of China(Nos.21671119,21301106 and 21673127)
文摘Under hydrothermal conditions, the reactions of NiII/CuII ions with 3-（6-aminpyri- dinium-3-yl） benzoate （HL） afford two compounds [NiL2]n （1） and [CuL2（H2O）]n （2）. On the basis of X-ray diffraction analysis of the two compounds, the results show that compound 1 features one-dimensional （1D） double-strand coordination arrays, while 2 presents the 63-hcb layers. Both compounds are further constructed into a 3D supramolecular structure with the aid of weak secondary interactions. Thermal stabilities and magnetic properties of compounds 1 and 2 were also investigated.
