Mechanical behaviour of Li_(3x)La_(1/3-x)NbO_3 with domain structure

摘要

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.