Robust narrow-gap semiconducting behavior in square-net La$_{3}$Cd$_{2}$As$_{6}$

Mario M. Piva; Marein C. Rahn; Sean M. Thomas; Brian L. Scott; Pascoal G. Pagliuso; Joe D. Thompson; Leslie M. Schoop; Filip Ronning; Priscila F. S. Rosa

doi:10.1021/acs.chemmater.1c00797

arXiv · 2108.08006

Robust narrow-gap semiconducting behavior in square-net La$_{3}$Cd$_{2}$As$_{6}$

Mario M. Piva·Marein C. Rahn·Sean M. Thomas·Brian L. Scott·Pascoal G. Pagliuso·Joe D. Thompson·Leslie M. Schoop·Filip Ronning·Priscila F. S. Rosa

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Abstract

ABSTRACT: Narrow-gap semiconductors are sought-after materials due to their potential for long-wavelength detectors, thermoelectrics, and more recently non-trivial topology. Here we report the synthesis and characterization of a new family of narrow-gap semiconductors, $R$$_{3}$Cd$_{2}$As$_{6}$ ($R=$ La, Ce). Single crystal x-ray diffraction at room temperature reveals that the As square nets distort and Cd vacancies order in a monoclinic superstructure. A putative charge-density ordered state sets in at 279~K in La$_{3}$Cd$_{2}$As$_{6}$ and at 136~K in Ce$_{3}$Cd$_{2}$As$_{6}$ and is accompanied by a substantial increase in the electrical resistivity in both compounds. The resistivity of the La member increases by thirteen orders of magnitude on cooling, which points to a remarkably clean semiconducting ground state. Our results suggest that light square net materials within a $I4/mmm$ parent structure are promising clean narrow-gap semiconductors.

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Mario M. Piva, Marein C. Rahn, Sean M. Thomas, Brian L. Scott, Pascoal G. Pagliuso, Joe D. Thompson, Leslie M. Schoop, Filip Ronning, Priscila F. S. Rosa. 2021-08-18. Robust narrow-gap semiconducting behavior in square-net La$_{3}$Cd$_{2}$As$_{6}$. https://doi.org/10.1021/acs.chemmater.1c00797

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