Mechanical behaviour of Li3xLa1/3−xNbO3 with domain structure

Abstract This study investigates the mechanical behaviours of A-site deficient perovskite-type Li3xLa1/3−xNbO3 electrolytes (3x = 0.00–0.18) with domain structures. The samples were examined under uniaxial compression in the temperature range of 233–393 K. In the stress vs. strain relationship, the orthorhombic Li3xLa1/3−xNbO3 (3x ≤ 0.06) clearly exhibits non-linear elastic hysteresis, whilst the tetragonal one (3x ≥ 0.12) shows a simple elastic behaviour. Ex-situ scanning electron microscopy observation on a polished surface before and after compression confirmed the martensitic reorientation of the domain structure of the orthorhombic Li3xLa1/3−xNbO3, which explains the observed non-linear hysteresis, whereas the domains of the tetragonal sample remain almost unchanged.