Structural dynamics of LaVO₃ on the nanosecond time scale

Area of Science:

• Materials Science
• Solid-State Physics
• Ultrafast Spectroscopy

Background:

• Electronic properties of materials are highly sensitive to local atomic structure.
• Understanding structural dynamics is crucial for ultrafast experiments.
• Perovskite materials are of interest due to their tunable electronic properties.

Purpose of the Study:

• To characterize the structural dynamics of a perovskite thin film (LaVO3) at nanosecond time scales.
• To refine structural parameters following optical excitation.
• To provide experimentally accessible values for structural and electronic tunability.

Main Methods:

• Combining optical excitation with time-resolved X-ray diffraction.
• Monitoring integer and half-integer diffraction peaks of LaVO3.
• Using an 800 nm pump pulse for above-band-gap excitation.

Main Results:

• Observed a 0.1% out-of-plane lattice expansion.
• Characterized relaxation dynamics with biexponential decay (2 and 12 ns time scales).
• Quantified small distortions: oxygen octahedral rotations decreased by ~0.3°, La displacements by ~0.2 pm, V-O-V bond angles increased by ~0.8°, and in-plane V-O bond lengths reduced by ~0.3 pm.

Conclusions:

• Demonstrated tracking of atomic positions in pump-probe experiments.
• Provided experimental values for structural and electronic tunability in perovskites.
• The findings will guide future research in ultrafast material dynamics.