Multiple aging mechanisms in ferroelectric deuterated potassium dihydrogen phosphate

The anomalously large dielectric aging in ferroelectric partially deuterated potassium dihydrogen phosphate is found to have multiple distinct mechanisms. Two components cause a decrease in dielectric response over a limited range of fields around the aging field. Substantial aging occurs on time scales of ∼1000 s after a field change, as expected for a hydrogen/deuterium diffusion mechanism. A slower component can give an almost complete loss of domain-wall dielectric response at the aging field after weeks of aging. There is also a particularly unusual aging in which the dielectric response increases with time after rapid cooling.