Magnetoelastic coupling behaviour of nanocrystalline ε-Fe2O3

•Spark Plasma Sintering of nanocrystalline ε-Fe2O3 results in distinct magnetisation.•Magnetic ordering below ∼500 K is accompanied by strains of up to ∼±0.002.•Elastic softening in response to stress fields is not seen at kHz-MHz frequencies.•Viscous motion of magnetic domain walls occurs in response to applied magnetic field.•ε-Fe2O3 potentially has functional piezoelectric and/or piezomagnetic properties.