Crack instability of ferroelectric solids under alternative electric loading

摘要: The low fracture toughness of the widely used piezoelectric and ferroelectric materials in technological applications raises a big concern about their durability safety. Up to now, mechanisms electric-field induced fatigue crack growth those are not fully understood. Here we report experimental observations that alternative electric loading at high frequency or large amplitude gives rise dramatic temperature tip solid. subsequently lowers energy barrier for domain switch vicinity tip, increases stress intensity factor leads unstable propagation finally. In contrast, small amplitude, mildly saturates quickly, no is observed. Together with our theoretical analysis on non-linear heat transfer constructed safe operating area curve respect field, validated safety map by experiments. revealed how electro-thermal-mechanical coupling influences can be directly guide design assessment devices.