Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1817898 | Physica C: Superconductivity and its Applications | 2013 | 6 Pages |
Abstract
We have systematically studied the substitution of nonmagnetic Zn and magnetic Ni at iron sites in Ce based oxypnictide. The parent compound (CeOFeAs) shows an anomaly in resistivity around 150Â K due to structural transition from tetragonal (space group: P4/nmm) to orthorhombic structure (space group: Cmma). Substitution of Zn suppresses this anomaly to lower temperature (â¼130Â K) but Ni substitution does not show any anomaly around this temperature and the compound behaves like a metal. Further, we find that non magnetic (Zn) doping leads to higher impurity scattering as compared to magnetic Ni doping. Similar to the resistivity measurement, the specific heat shows another jump near 4Â K for CeOFeAs. This is attributed to the ordering of Ce3+ moments. This peak shifts to 3.8Â K for Zn substituted compound and there is no change in the ordering temperature in the Ni substituted CeOFeAs. These peaks are broadened in applied magnetic field (5Â T) and the calculated magnetic entropy tends to saturate at the same value for 0Â T and 5Â T external magnetic field.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
S.J. Singh, Jai Prakash, A. Pal, S. Patnaik, V.P.S. Awana, A.K. Ganguli,