Friction Anomalies at First-Order Transition Spinodals: 1T-TaS${}_2$

Abstract

Revealing phase transitions of solids through mechanical anomalies in the friction of nanotips sliding on their surfaces is an unconventional and instructive tool for continuous transitions, unexplored for first-order ones. Owing to slow nucleation, first-order structural transformations generally do not occur at the precise crossing of free energies, but hysteretically, near the spinodal temperatures where, below and above the thermodynamic transition temperature, one or the other metastable free energy branches terminates. The spinodal transformation, a collective one-shot event with no heat capacity anomaly, is easy to trigger by a weak external perturbations. Here we propose that even the gossamer mechanical action of an AFM tip may locally act as a surface trigger, narrowly preempting the spontaneous spinodal transformation, and making it observable as a nanofrictional anomaly. Confirming this expectation, the CCDW-NCCDW first-order transition of the important layer compound 1T-TaS${}_2$ is shown to provide a demonstration of this effect.

8 pages, 5 figures

References in corpus (5)

• Is 1T-TaS${}_2$ a 40 year old quantum spin liquid?
• A new high-temperature quantum spin liquid with polaron spins
• Atomic Lattice Disorder in Charge Density Wave Phases of Exfoliated Dichalcogenides (1T-TaS2)
• Gapless excitations in the ground state of 1T-TaS${}_2$
• The low-temperature highly correlated quantum phase in the charge-density-wave 1T-TaS_2 compound

Cited by in corpus (1)

• Nonmonotonic Magnetic Friction from Collective Rotor Dynamics