Atom movement in In3La studied via nuclear quadrupole relaxation

Area of Science:

• Solid-state physics
• Materials science
• Nuclear physics

Background:

• Understanding atomic diffusion in intermetallic compounds like In3La is crucial for materials science.
• Tracer atom studies provide insights into diffusion mechanisms and kinetics.
• The In3La system exhibits complex phase boundaries relevant to diffusion studies.

Purpose of the Study:

• To measure the jump frequencies of Cadmium (Cd) tracer atoms in the In3La intermetallic compound.
• To investigate the influence of phase boundaries on atomic diffusion.
• To elucidate the underlying diffusion mechanisms in In3La.

Main Methods:

• Utilized the perturbed angular correlation (PAC) of gamma rays technique.
• Measured nuclear quadrupole relaxation due to stochastic reorientation of the electric field gradient.
• Analyzed relaxation data to determine activation enthalpies and jump frequencies.

Main Results:

• Identified two distinct phase boundaries in In3La with a small compositional difference (~0.1 at. %).
• Determined activation enthalpies for Cd tracer atom diffusion at these boundaries: 0.53(1) eV and 0.81(1) eV.
• Observed significantly higher jump frequencies at the more Indium-rich phase boundary.

Conclusions:

• The observed diffusion behavior, particularly the higher jump frequency at the Indium-rich boundary, rules out a simple Indium-vacancy diffusion mechanism.
• The findings suggest complex diffusion pathways in the In3La system.
• The perturbed angular correlation method proves effective for studying jump frequencies and diffusion mechanisms in intermetallic compounds.