1. Thickness-dependent nanoscale friction across the first-order charge density wave phase transition in 1T-TaS2.
- Author
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Liu, Changtao and Wang, Wen
- Subjects
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PHASE transitions , *CHARGE density waves , *ATOMIC force microscopy , *RAMAN spectroscopy , *FRICTION - Abstract
The layered charge density wave (CDW) phase transition material 1T-TaS 2 has garnered significant attention due to its modulable bandgap and electrical transport properties. These unique properties make 1T-TaS 2 highly promising for applications in fields such as optoelectronic devices and microstructure physics devices. In various micro-/nanodevices made from quasi-two-dimensional 1T-TaS 2 , it is often utilized in thin layers, making the understanding of its frictional properties crucial for practical applications. However, the layer-dependent frictional properties of 1T-TaS 2 have not been thoroughly investigated. In this article, we examine the CDW phase transition between the nearly commensurate (NCCDW) and commensurate (CCDW) phases in 1T-TaS 2 around 183 K using atomic force microscopy, focusing on the number of layers in the samples. Our results indicate that for thicker samples with more than approximately 17 layers, a friction peak is observed during the NCCDW–CCDW phase transition. In contrast, thinner samples do not exhibit this friction peak, and their friction continuously increases as the temperature decreases. This behavior is attributed to the suppressed NCCDW–CCDW phase transition in thinner samples. These results enhance our understanding of the frictional behavior of 1T-TaS 2 in the context of micro-/nano-electromechanical systems. Furthermore, our observations offer a straightforward method to identify the NCCDW–CCDW phase transition, providing an alternative to traditional, more complex techniques such as electrical resistance measurements and Raman spectroscopy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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