Uniaxial strain-driven ferroelastic domain control in LaAlO3

TL;DR

This study demonstrates reversible control of ferroelastic domains in LaAlO3 using in-situ uniaxial strain, enabling real-time domain engineering with potential applications in electronics and photonics.

Contribution

It introduces a method for continuous, reversible manipulation of ferroelastic domains in LaAlO3 via uniaxial strain, combining experimental and theoretical techniques.

Findings

Strain below 0.5% causes significant domain reorganization.

Uniaxial strain enables surface flattening and domain control.

Results suggest potential for active domain architecture programming.

Abstract

Multiferroic domain walls in functional oxides exhibit properties distinct from the bulk and are increasingly exploited as active elements in nanoelectronic and photonic devices. Deterministic control of domain populations has typically remained limited to local control, or removal with temperature. Here we demonstrate continuous, reversible manipulation of the ferroelastic domain structure in single-crystal LaAlO$_3$ using in-situ uniaxial strain. Combining atomic force microscopy, X-ray diffraction, and Raman spectroscopy with first-principles calculations we map the complete microscopic evolution of the twin domain population through the strain-driven transition from the rhombohedral $R\bar{3}c$ ground state toward the predicted orthorhombic $Fmmm$ phase. Applied strains below $0.5\%$ produce pronounced surface flattening and large-scale domain reorganisation, establishing uniaxial strain as a technically accessible control parameter for ferroelastic domain engineering. These results open a route to active, real-time programming of domain architectures in LaAlO$_3$-based heterostructures, with implications for strain-tunable superconducting interfaces, nanoscale phonon-polariton optics, and ultrafast lattice control.