Electrical transport properties of CaB6
- Author(s): Stankiewicz, J
- Sesé, J
- Balakrishnan, G
- Fisk, Z
- et al.
Published Web Locationhttps://doi.org/10.1103/PhysRevB.90.155128
© 2014 American Physical Society. We report results from a systematic electron-transport study in a broad temperature range on 12 CaB6 single crystals. None of the crystals were intentionally doped. The different carrier densities observed presumably arise from slight variations in the Ca:B stoichiometry. In these crystals, the variation of the electrical resistivity and of the Hall effect with temperature can be consistently accounted for by the model we propose, in which B-antisite defects (B atom replacing Ca atom) are "amphoteric." The magnetotransport measurements reveal that most of the samples we have studied are close to a metal-insulator transition at low temperatures. The magnetoresistance changes smoothly from negative - for weakly metallic samples - to positive values - for samples in a localized regime.