Direct current-voltage failure of lead-based relaxor ferroelectrics with silver doping

The effect of silver doping on the DC-voltage resistance failure of lead-based relaxor ferroelectrics was investigated via temperature-humidity-bias (THB) testing, scanning electron microscopy, X-ray diffraction spectroscopy, and electrical measurements. The failure rate of silver-doped specimens was found to increase significantly with the doping level during the THB test. However, some degraded specimens can partially recover their electrical properties after a few days of storing in natural conditions. X-ray diffraction analysis showed that silver could be incorporated into the perovskite lattice in the range of silver contents studied. The presence of an inner-bias field in the degraded ceramics was first demonstrated through hysteresis property measurement. Based on these results, it was inferred that the accumulation of oxygen vacancies under DC-voltage should be responsible for the inner-bias field, which consequently resulted in the increase of electronic defects in the ceramics.