Normal and abnormal domains induced by electron-beam irradiation in Sr0·61Ba0·39Nb2O6 crystals.

Ferroelectric domain structures induced by electron-beam irradiation of the polar surface of SBN (Sr 0·61 Ba 0·39 Nb 2 O 6) crystals have been investigated. The domains were observed in the low-voltage SEM mode and by PFM. The effect of electron-beam irradiation at U = 25 kV and 10 kV on the growth of domains in polydomain (zero field-cooled) and monodomain (field-cooled) samples was compared. Stable electron-beam domains were formed after prolonged irradiations and in high intensity electric fields (E z > > E c). It was found that the time threshold for the formation of stable domains in monodomain samples was significantly higher than in polydomain ones. The increase in domain diameter (d) with irradiation time followed an exponential dependence in both types of samples. However, the parameters of the dependences were different. An abnormal PFM contrast was found in the domains of zero field-cooled samples after prolonged irradiation at U = 25 kV. The relationship between the size of the oval domains formed in different SBN samples and the embedded regions of space charge, as well as the distribution and magnitude of the generated electric field strength (E z) was analyzed by computer simulation. The abnormal domain contrast observed in the experiment was attributed to the calculated inversion of the E z field in the surface layer and the polydomain structure of the irradiated sample. • Domains and periodic domain structures have been produced in Sr 0·61 Ba 0·39 Nb 2 O 6 (SBN) by electron beam irradiation. • Domain growth kinetics for initial monodomain and polydomain SBN samples investigated. • Conditions for anomalous domain formation during electron beam domain engineering are revealed. • The modeling of the electric field distribution for different irradiation regimes and recording schemes is considered. [ABSTRACT FROM AUTHOR]