Nanoscale domain engineering in ferroelectriccrystals is demonstrated down to a lateral domain size of 25 nmin diameterusing scanning force microscopy (SFM). The variousmodes of SFM are used to measure both the intermal polarizationfield and external stray field arising from bound surface chargesin ferroelectric domains. From these measurements the effectivethree-dimensional arrangement of ferroelectric domains isreconstructed. Domain switching is initiated applying strongelectric fields between the tip and counter electrode. The size offreshly nucleated domains is found to depend dramatically on theswitching conditions, i.e., the applied electric field strength andswitching time. Domains of less than 100 nm in diameter resultfor an electric field Eexp > 50kV cm-1 applied applied for an ultra-short time periodτexp<30μs. Also, the coercive field ofnanoscale ferroelectric domains in BaTiO3 single crystals isfound to measure 1.4kV cm-1,much more than the bulk value.Analysis of the transient response during domain switchingshows that domain nucleation proceeds within less than 100μs.With these tools we are able to record nanoscale hysteresis loopsmonitoring both the successful domain reversal and a wellestablished material contrast between different ferroelectricstructures with a resolution of better than 0.1%.
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