Abstract
The spinel-type exhibits heavy-fermion metallic behaviors at low temperatures, but the effect of composition modulation on them is unknown. We realized the epitaxial growth of highly crystalline films and conducted the electrochemical Li-ion intercalation (electron doping) to investigate systematic variation of transport properties in . We found that adjustment of Li content during pulsed-laser deposition was important to obtain films exhibiting the heavy-fermion metallic behavior comparable to that of a bulk single crystal. At low doping regime , resistivity increased with increasing electron filling. The slope of their linear dependence also increased in accordance of a Fermi-liquid model. At high doping regime , a Mott transition was observed over a range of Li content where a new spinel phase and the original one coexisted. The results revealed that the electron doping induced enhancement of the electron correlation and the resultant Mott transition.
- Received 4 December 2020
- Revised 16 September 2021
- Accepted 15 November 2021
DOI:https://doi.org/10.1103/PhysRevB.104.245104
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