Abstract
We performed point-contact spectroscopy tunneling measurements on single crystal for at temperatures and find a suppression in the density of states at low bias voltages that is characteristic of disordered metals. Both the correlation gap and the zero-temperature conductivity are zero at a critical concentration . Not only does this suggests that a disorder driven metal-insulator transition occurs before the onset of the charge disproportionated charge density wave insulator, but we also explore whether a scaling theory is applicable. In addition, we estimate the disorder-free critical temperature and compare these results to .
- Received 17 November 2013
DOI:https://doi.org/10.1103/PhysRevLett.113.177004
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