Pressure Control of Nonferroelastic Ferroelectric Domains in ErMnO₃

Mechanical pressure controls the structural, electric,and magneticorder in solid-state systems, allowing tailoring of their physicalproperties. A well-established example is ferroelastic ferroelectrics,where the coupling between pressure and the primary symmetry-breakingorder parameter enables hysteretic switching of the strain state andferroelectric domain engineering. Here, we study the pressure-drivenresponse in a nonferroelastic ferroelectric, ErMnO3, wherethe classical stress-strain coupling is absent and the domainformation is governed by creation-annihilation processes oftopological defects. By annealing ErMnO3 polycrystals undervariable pressures in the MPa regime, we transform nonferroelasticvortex-like domains into stripe-like domains. The width of the stripe-likedomains is determined by the applied pressure as we confirm by three-dimensionalphase field simulations, showing that pressure leads to oriented layer-likeperiodic domains. Our work demonstrates the possibility to utilizemechanical pressure for domain engineering in nonferroelastic ferroelectrics,providing a lever to control their dielectric and piezoelectric responses.