We studied the effects of nickel (Ni) doping on the magneto-transport properties of Sm0.55Sr0.45MnO3 manganites near the metal-insulator transition. Various concentrations of Ni-doped Sm0.55Sr0.45MnO3 samples up to 10% were prepared (Ni was partially substituted at the Mnsite). The temperature dependence of resistivity and magnetoresistance were measured as a function of Ni concentrations at various applied magnetic fields. We observed a nonlinear reduction of the metal-insulator transition temperature (MIT) with increasing concentration of Ni, 5% of Ni was sufficient to completely suppress the insulatormetal transition. Moreover, we observed dramatic increases of the resistance of the doped material with an increasing Ni-doping (5% of Ni increases R by more than 1000 times). The resistivity peaks at various magnetic fields collapses on themselves at the high temperature ends above the MIT. We also performed magnetization versus temperature measurements on both Ni-free the Ni-doped samples for FC and ZFC states. The FC and ZFC curves rapidly decrease to paramagnetic state at 175 K and 130 K for ZFC and FC states, respectively. For other Ni-doped samples, we observed a reduction in the paramagnetic transition temperature with increasing Ni concentration.
Bibliographical noteFunding Information:
Acknowledgements The authors would like to acknowledge support from both the University of Alberta, Canada (where some measurements were made), and King Fahd University of Petroleum and Minerals (KFUPM).
- Magnetic materials doping
- Manganese oxides
- Transport properties
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics