Slow dynamics and anomalous nonlinear fast dynamics in diverse solids

Area of Science:

• Solid-state physics
• Materials science
• Nonlinear dynamics

Background:

• Nonlinear mesoscopic elasticity describes complex material behaviors.
• Anomalous nonlinear fast dynamics (ANFD) and slow dynamics (SD) are distinct phenomena.
• Previous studies have not systematically investigated the co-occurrence of ANFD and SD.

Purpose of the Study:

• To systematically investigate the simultaneous occurrence of ANFD and SD in various solid materials.
• To determine if ANFD and SD are linked phenomena.
• To identify material characteristics related to these nonlinear dynamics.

Main Methods:

• Experimental observation of ANFD and SD in seven diverse solid materials.
• Measurement of amplitude-dependent internal friction and resonance frequency shift.
• Analysis of the ratio of internal friction to resonance frequency shift as a function of strain amplitude and time.

Main Results:

• ANFD and SD were observed to occur together in all seven materials studied, including gray iron, alumina ceramic, quartzite, cracked Pyrex, marble, sintered metal, and perovskite ceramic.
• Materials exhibiting ANFD showed a consistent ratio of internal friction to resonance frequency shift (0.28-0.63), suggesting a material characteristic, with cracked Pyrex as an outlier (1.1).
• The ratio of internal friction to resonance frequency shift during SD was time-independent and ranged from 0.23 to 0.43 across the studied materials.

Conclusions:

• The co-occurrence of ANFD and SD significantly expands the known class of nonlinear mesoscopic elasticity.
• The ratio of internal friction to resonance frequency shift appears to be a characteristic property of materials exhibiting ANFD.
• The findings provide new insights into the fundamental nonlinear behaviors of solid materials.