A Natural 2D Heterostructure [Pb 3.1 Sb 0.9 S 4 ][Au x Te 2–x ] with Large Transverse Nonsaturating Negative Magnetoresistance and High Electron Mobility
- Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division
- Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering
- Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division
- Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering
- Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry, and Dept. of Materials Science and Engineering; Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division
We report the two-dimensional (2D) natural hetero-structure [Pb3.1Sb0.9S4][Au$$_x$$Te$$_{2-x}$$] ($$x$$ = 0.52-0.36) which shows anomalous, transverse nonsaturating negative magnetoresistance (MR). For $$x$$ = 0.52, the material has a commensurately modulated structure with alternating [Pb3.1Sb0.9S4] rocksalt layers and atomically thin [Au$$_x$$Te$$_{2-x}$$] sheets, as determined by single-crystal X-ray diffraction using a (3 + 1)-dimensional space group; for other $$x$$ compositions, the modulated structure is absent and the Au and Te atoms are disordered. The transport properties in this system at low temperature (<100 K) are dominated by an unusual 2D hopping mechanism, while at room temperature a high carrier mobility of similar to ~1352 cm2 V-1 s-1 obtained ($$x$$ = 0.36). The confined electrons within the [Au$$_x$$Te$$_{2-x}$$] layers are also exposed to interlayer coupling with the insulating [Pb3.1Sb0.9S4] layers, and as a result, the properties of the heterostructures emerge not only from the constituent layers but also the interactions between them. Furthermore, the various Au and Te coordination patterns found in the [Au$$_x$$Te$$_{2-x}$$] sheets as a function of $$x$$ further contribute to a unique electronic structure that leads to the anomalous nonsaturating negative MR with different field dependent behaviors. First-principles calculations indicate that the [Au$$_x$$Te$$_{2-x}$$] sheets are responsible for the unusual electrical transport properties in this 2D system.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1524424
- Journal Information:
- Journal of the American Chemical Society, Vol. 141, Issue 18; ISSN 0002-7863
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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