1,720,997 research outputs found
Quantitative measurement of in-plane cantilever torsion for calibrating lateral piezoresponse force microscopy
No full textA simple quantitative measurement procedure of in-plane cantilever torsion for calibrating lateral piezoresponse force microscopy is presented. This technique enables one to determine the corresponding lateral inverse optical lever sensitivity (LIOLS) of the cantilever on the given sample. Piezoelectric coefficient, d(31) of BaTiO(3) single crystal (-81.62 +/- 40.22 pm/V) which was calculated using the estimated LIOLS was in good agreement with the reported value in literature. c 2011 American Institute of Physics.
Surface potential of ferroelectric domain investigated by kelvin force microscopy
No full textWe have investigated the surface potential of poled area by varying the poled size and the sign of applied voltage on 100 nm thick Pb(Zr0.25Ti0.75)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.Samsung Advanced Institute of Technology
Channel Thickness-Dependent Degradation of Field-Effect Mobility in Multilayer MoS2 Transistors
No full textTwo-dimensional(2D) semiconductorssuch as molybdenumdisulfide(MoS2) may serve as state-of-the-artlogicdevicesas we progresstowardthe 2 nm technologynode. Here, we show that mobilitydegradationis influencedby the channelthicknessof multilayerMoS2transistors.ThickerMoS2channelsexhibitedless degradationof field-effectmobilitycaused by thetransverseelectricfield (E-field),given the considerablebulk conductioncurrent.Kelvin probe force microscopy(KPFM)was usedto measurethe channelthickness-dependentcontactpotentialdifferencegradient.Numericalsimulationconfirmedthat the verticalE-field was well screenedby the bulk conductionchannel.The results enhanceour understandingof multilayerMoS2transistoroperationand will enable performanceoptimization.
Effect of cantilever-sample interaction on piezoelectric force microscopy
No full textWe report on the evidence for the cantilever-sample (CS) capacitive force contribution to the piezoelectric force microscopy (PFM). In addition, we present that positioning of the tip near the edge of the sample surface can significantly reduce this spurious contribution for any combinations of tip cantilever and film. As proof of both the existence of CS interaction and its reduction, the domains formed by the application of voltage pulses through the tip are observed by PFM at two different positions, i.e., sample center and edge. In accordance with the model that a piezoresponse consists of a piezoelectric vibration of the film and an electrostatic force induced vibration of cantilever, the domain contrasts are characterized by dot structure in the amplitude and negligible contrast in the phase images when the tip is placed in the center of the sample surface. However, reducing the CS interaction by placing the tip near the sample edge yields domain contrasts showing ring structure in the amplitude and a clear 180degrees phase shift in the phase images. Accompanying resolution enhancement in phase images results in smaller size of domains (bits) produced by identical voltage pulses as is evidenced from bit size estimation. Additional evidence for reduction of CS interaction is obtained from piezoresponse hysteresis measurement. (C) 2002 American Institute of Physics.
Interfacial Engineering Using a Thiophene-based Electrolyte Additive for High-Voltage Lithium-Ion Batteries
No full textEffects of surface morphology on retention loss of ferroelectric domains in poly(vinylidenefluoride-co-trifluoroethylene) thin films
No full textEffects of surface morphology on the retention loss of ferroelectric domains of poly(vinylidenefluoride-co-trifluoroethylene) thin films were investigated using piezoresponse force microscopy. We found that the retention loss occurred by nucleation of opposite domains at the regions with morphological gradients between 0.079 and 0.146. In addition, we observed collective decreases in piezoresponse amplitude of the opposite domains after 0.8 x 10(6) s, although each reversed domain showed different growth rate as evidenced by different threshold time for phase reversal. These results suggest that the surface morphology has a strong influence in determining the nucleation and growth kinetics by which the retention loss occurs. (C) 2011 American Institute of Physics.
- …
