Driving rate effects in avalanche-mediated first-order phase transitions

Area of Science:

• Condensed Matter Physics
• Materials Science
• Statistical Mechanics

Background:

• First-order phase transitions exhibit avalanches characterized by power-law distributions.
• Understanding the factors influencing these avalanche dynamics is crucial for materials science and condensed matter physics.

Purpose of the Study:

• To investigate the dependence of power-law exponents on driving rate and temperature in first-order phase transitions.
• To establish a general framework explaining the observed avalanche behavior in terms of competing time scales.
• To validate findings through numerical simulations.

Main Methods:

• Experimental measurements of acoustic emission during structural transitions in Cu-Zn-Al and Cu-Al-Ni alloys.
• Theoretical analysis based on a general framework of competing time scales.
• Numerical simulations of a prototype model.

Main Results:

• The power-law exponents characterizing avalanche distributions show clear dependence on driving rate and temperature.
• A general framework successfully explains the observed behavior by considering the interplay of avalanche relaxation, driving rate, and thermal fluctuations.
• Numerical simulations confirm the experimental findings and theoretical framework.

Conclusions:

• The driving-rate and temperature dependence of avalanche exponents in first-order phase transitions can be understood through a unified framework of competing time scales.
• Acoustic emission measurements provide valuable insights into the dynamics of structural transitions.
• The study offers a comprehensive understanding of avalanche phenomena in phase transitions.