caa a22 4500 445380543 CHVBK 20180317143016.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s10948-010-0834-5 doi (NATIONALLICENCE)springer-10.1007/s10948-010-0834-5 Magnetic and Mössbauer Studies of Ba(Fe1− x Ni x )2As2 Single Crystals [Elektronische Daten] [I. Felner, I. Nowik] Magnetization and 57Fe Mössbauer effect spectroscopy (MS) studies of Ba(Fe1−x Nix)2As2 single crystals (x=0 to 0.054) at temperatures (5K to 300K) have been performed. Magnetic measurements show that for BaFe2As2 the magnetic moment decreases below T N=136K. T Nis suppressed monotonically by Ni doping. On the other hand, for higher x values the magnetic moment increases belowT N. Unexpectedly for x=0.024 (T N=67K), the virgin zero-field-cooled (ZFC) curve is higher than that of field-cooled (FC) one below 48K. The magnetic MS spectra of this sample are composed of a superposition of two subspectra, corresponding to commensurate and incommensurate field distributions. The average magnetic hyperfine field H eff decreases with T and becomes zero at 80K. For higher x values, the samples become superconducting at T C=15.5 and 19K for x=0.046 and 0.054, respectively. For both samples below T C, the FC curves are positive (the paramagnetic Meissner effect) up to applied field of H∼15 Oe and the susceptibility is inversely proportional toH. The MS spectra below and above T C are almost identical, indicating that the MS parameters are not sensitive enough to detect the superconducting state. The peculiar phenomena observed are attributed to disorder induced by the presence of Ni atoms in the Fe sublattice. Springer Science+Business Media, LLC, 2010 Superconductivity nationallicence Spin wave density nationallicence Paramagnetic Meissner effect nationallicence Felner I. Racah Institute of Physics, The Hebrew University, 91904, Jerusalem, Israel aut Nowik I. Racah Institute of Physics, The Hebrew University, 91904, Jerusalem, Israel aut Journal of Superconductivity and Novel Magnetism Springer US; http://www.springer-ny.com 24/4(2011-05-01), 1363-1369 1557-1939 24:4<1363 2011 24 10948 https://doi.org/10.1007/s10948-010-0834-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10948-010-0834-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Felner I. Racah Institute of Physics, The Hebrew University, 91904, Jerusalem, Israel aut NATIONALLICENCE 700 1- Nowik I. Racah Institute of Physics, The Hebrew University, 91904, Jerusalem, Israel aut NATIONALLICENCE 773 0- Journal of Superconductivity and Novel Magnetism Springer US; http://www.springer-ny.com 24/4(2011-05-01), 1363-1369 1557-1939 24:4<1363 2011 24 10948 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer