Surface potential of ferroelectric domain investigated by kelvin force microscopy

Abstract

We have investigated the surface potential of poled area by varying the poled size and the sign of applied voltage on 100 nm thick Pb(Zr 0.25 Ti 0.75 )O 3 films grown by chemical solution deposition using Kelvin force microscopy (KFM). In the negative poled area, as the poled size increases from 300 to 4800 nm, the domain size and the KFM contrast increased in a linear way. However, in the positive poled area, the KFM contrast increased at first and then didn't increase because of Coulomb repulsion. In two opposite poled areas, the values of the KFM contrast differed because of the internal field near the ferroelectric/electrode interface. These results imply that the surface overcharge of poled area in ferroelectric materials should be increased and the ferroelectric/electrode interface should be improved for the ultra high-density memory device.

Design of a molecular memory element with an alternating circular array of dipolar rotors and rotation suppressors

“…Since both isomers were conformationally stable in solution at room temperature, highperformance liquid chromatography of the resulting mixture allowed the isolation of 1 3,0 and 1 2,1 in 5 and 2% yields, respectively. The structures of these compounds including the conguration of their diuorophenyl rings were successfully identied by 1 H, 13 C and 19 F NMR spectroscopy (ESI †). All three diuorophenyl groups in 1 3,0 are oriented in the same direction, while in 1 2,1 , one of the diuorophenyl groups is oriented in the opposite direction to the other diuorophenyl groups (Fig.…”

Design and preparation of stress-free epitaxial BaTiO3polydomain films by RF magnetron sputtering

“…Such a polydomain structure usually has highly mobile domain walls and can be very adaptive to an applied field [7,18]. The main methods of studying the domain structures of ferroelectric thin films include surface modification [19], optical microscopy [19,20], scanning electron microscopy [19,21] and scanning probe microscopy [19,[21][22][23]. Many researchers used advanced optical microscopy techniques to observe domain structures in ferroelectric films, including polarization optical microscopy [3,24], near-field optical microscopy [20] and second-harmonic generation microscopy [25,26].…”

Orientation-dependent surface potential behavior in Nb-doped BiFeO3

“…The asymmetry of the surface potential behaviors can stem from the presence of an internal built-in electric field near the multiferroic/electrode interface, different screen charge of as-grown rate, and different amounts of trap sites. 13,14 Meanwhile, with increasing positive voltage, more holes are injected, and we get saturated screen charges at about 8 V. Further increasing the positively biased voltage to þ10 V, the amplitude of surface potentials decreases gradually due to the overscreen charges. 4 For the negative biased regions, negative surface potentials are obtained due to electrons trapping effect.…”