Relaxation time measurement: correlating diffraction patterns.

Area of Science:

• Condensed matter physics
• Materials science
• Soft matter physics

Background:

• X-ray photon correlation spectroscopy (XPCS) and electron correlation microscopy are key techniques for studying dynamics in liquids and glasses.
• These methods rely on analyzing temporal changes in diffraction patterns.
• Current understanding of one-time and two-time correlation functions for evaluating these dynamics is limited.

Purpose of the Study:

• To investigate and compare the characteristics of one-time and two-time correlation functions.
• To determine the advantages of each method for analyzing dynamics in liquids and glasses.

Main Methods:

• Utilized X-ray photon correlation spectroscopy (XPCS) and electron correlation microscopy.
• Measured temporal changes in diffraction patterns.
• Calculated and compared one-time and two-time correlation functions.

Main Results:

• The two-time correlation function enables the measurement of dynamics over extended periods compared to the one-time correlation function.
• The two-time correlation function demonstrated a low sensitivity to the applied radiation dose.

Conclusions:

• The two-time correlation function is a more robust method for probing long-timescale dynamics in liquids and glasses.
• Its weak dose dependence enhances its applicability in various experimental settings.