1. Sign reversal of magnetoresistance in a perovskite nickelate by electron doping
- Author
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Yong P. Chen, Shriram Ramanathan, Jiangpin Hu, Koushik Ramadoss, Zhong Wan, Nirajan Mandal, Leonid P. Rokhinson, X. F. Dai, and You Zhou
- Subjects
Materials science ,Colossal magnetoresistance ,Magnetoresistance ,Condensed matter physics ,Doping ,Order (ring theory) ,Ionic bonding ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Variable-range hopping ,Condensed Matter::Materials Science ,Electrical resistivity and conductivity ,Condensed Matter::Superconductivity ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,0210 nano-technology ,Perovskite (structure) - Abstract
We present low temperature resistivity and magnetotransport measurements conducted on pristine and electron doped ${\mathrm{SmNiO}}_{3}$ (SNO). The low temperature transport in both pristine and electron-doped SNO shows a Mott variable range hopping with a substantial decrease in localization length of carriers by one order in the case of doped samples. Undoped SNO films show a negative magnetoresistance (MR) at all temperatures characterized by spin fluctuations with the evolution of a positive cusp at low temperatures. In striking contrast, upon electron doping of the films via hydrogenation, we observe a crossover to a linear nonsaturating positive $\mathrm{MR}\ensuremath{\sim}0.2%$ at 50 K. The results signify the role of localization phenomena in tuning the magnetotransport response in doped nickelates. Ionic doping is therefore a promising approach to tune magnetotransport in correlated perovskites.
- Published
- 2016
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