Nonresonant dielectric hole-burning spectroscopy on a titanium-modified lead magnesium niobate ceramic - art. no. 054103

Nonresonant dielectric hole-burning experiments were performed on the titan ium-modified relaxor ferroelectric lead magnesium niobate around the diffus e maximum in the dielectric permittivity. After applying large alternating electric pump fields we monitored the polarization response to small field steps for times between 0.3 ms and 100 s. Depending on the frequency of the pump oscillation a speedup of the polarization response was observed with a maximum located around times corresponding to the inverse pump frequency. The refilling of the dielectric holes was investigated for several tempera tures, pump frequencies. and pump field amplitudes. It proceeded always slo wer than the time scale set by the pump frequencies. Additionally, we obser ve a significant increase of the refilling times for increasing pump field amplitudes. This finding can be interpreted to indicate that increasingly l arge pump fields enable the domain walls to cross larger and larger pinning barriers. The subsequent recovery process, which leads back to the equilib rium domain size distribution, proceeds in the absence of an external elect rical field. This rationalizes that recovery is slowed down significantly b y application of large pump field amplitudes since then the pinning barrier s that have to be traversed back are larger.