Wednesday, 23 January 2019

Anomalous magnetoresistance of Bi doped La0.67Sr0.33MnO3

N. Kambhala, S.S. Samatham, R. Venkatesh, V. Ganesan, S. Angappane
Phys. Status Solidi B, 1700194 (2017); (DOI: 10.1002/pssb.201700194).

 Anomalous magnetoresistance of Bi doped La0.67Sr0.33MnO3

Temperature dependence of the resistance with different applied magnetic fields, H= 0, 5 and 10 T of La0.67-xBixSr0.33MnO3 (x=0, 0.1, 0.2, 0.3, 0.4, 0.5).

We have studied the magnetotransport properties of La0.67-xBixSr0.33MnO3 (x=0, 0.3, 0.4, 0.5). The x ≤ 0.3 samples show the metal-insulator transitions, while x ≥ 0.4 samples exhibit an insulating behaviour at zero field. Notably, two low-temperature upturns observed for La0.37Bi0.3Sr0.33MnO3, which indicates the existence of two different mechanisms. La0.27Bi0.4Sr0.33MnO3 shows the field induced metallic behaviour due to the melting of charge ordering with applied magnetic field. The large magnetoresistance of ~ 100 % was observed for La0.27Bi0.4Sr0.33MnO3 at ~ 90 K. On the other hand, La0.37Bi0.3Sr0.33MnO3 exhibits a nearly constant large MR of ~ 80 % between ~ 30 and 250 K, which decreases out-side this temperature range. The observed anomalous low-temperature magnetotransport properties of La0.67-xBixSr0.33MnO3 is shown to arise from the coexisting phases of ferromagnetic metallic and antiferromagnetic charge ordered insulating states.