An atomic-level view of melting using femtosecond electron diffraction

Area of Science:

• Materials Science
• Condensed Matter Physics
• Physical Chemistry

Background:

• Understanding ultrafast phase transitions is crucial for materials science.
• Laser-induced melting provides a pathway to study solid-liquid dynamics.
• Atomic-level insights into melting dynamics are often challenging to obtain.

Purpose of the Study:

• To investigate the structural evolution of aluminum during an ultrafast laser-induced solid-liquid phase transition.
• To capture real-time atomic dynamics during melting at the picosecond timescale.
• To provide an atomic-level description of the melting process under strongly driven conditions.

Main Methods:

• Utilized 600-femtosecond electron pulses for probing.
• Employed time-resolved electron diffraction to observe structural changes.
• Measured the time-dependent pair correlation function to track atomic order.

Main Results:

• Observed the loss of long-range crystalline order and emergence of liquid structure.
• Documented the solid-liquid transition occurring within 3.5 picoseconds.
• Captured the evolution of atomic correlations from solid to liquid states.

Conclusions:

• The melting dynamics of aluminum under strong laser driving are best understood as a thermal phase transition.
• Provided unprecedented atomic-level detail of the melting process.
• Demonstrated the capability of femtosecond electron pulses for studying ultrafast material transformations.