Amorphization of Gd2Zr2O7 induced by mechanical deformation in nanoindentation

Amorphization has become an important plastic deformation mechanism for covalently-bonded ceramics, which can disturb their crystalline order and affect their mechanical behaviors. Unlike the covalently-bonded ceramics, however, amorphization induced by mechanical deformation is rarely observed in ionically-bonded ceramics. In this work, we show direct experimental evidence that nano-scale amorphous zones in Gadolinium Zirconate ceramic are the ultimate stage of plasticity and relate to an accumulation of dislocations. In addition, the occurrence of amorphization also causes the unusual indentation size effect.