Athermal character of structural phase transitions.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Physical Chemistry

Background:

• Structural first-order phase transitions involve nucleation, a process influenced by thermal fluctuations.
• Martensitic transitions serve as a key experimental model for studying these phenomena.
• Understanding nucleation mechanisms is crucial for controlling material properties.

Purpose of the Study:

• To investigate the role of thermal fluctuations in nucleation during structural first-order phase transitions.
• To experimentally examine martensitic transitions using acoustic emission techniques.
• To develop a theoretical framework explaining observed transition behaviors.

Main Methods:

• Experimental investigation of martensitic transitions via acoustic emission.
• Development of a theoretical model based on mean first-passage time analysis.
• Analysis of conditions leading to isothermal and athermal transitions.

Main Results:

• Acoustic emission data provided insights into the nucleation dynamics of martensitic transitions.
• The mean first-passage time model successfully accounted for experimental observations.
• The study established a unified framework for understanding transition mechanisms.

Conclusions:

• Thermal fluctuations play a critical role in the nucleation process of first-order phase transitions.
• The proposed model offers a comprehensive approach to studying isothermal and athermal transitions.
• This research provides a foundation for predicting and controlling phase transformation behaviors.