Impact of the tip radius on the lateral resolution in piezoresponse force microscopy

Abstract

We present a quantitative investigation of the impact of tip radius as well as sample type and thickness on the lateral resolution in piezoresponse force microscopy (PFM) investigating bulk single crystals. The observed linear dependence of the width of the domain wall on the tip radius as well as the independence of the lateral resolution on the specific crystal-type are validated by a simple theoretical model. Using a Ti-Pt-coated tip with a nominal radius of 15 nm the so far highest lateral resolution in bulk crystals of only 17 nm was obtained.

Radiation-damage-assisted ferroelectric domain structuring in magnesium-doped lithium niobate

“…2 shows that radiation damage enables smaller domain generation in irradiated material as compared to untreated crystals: in the non-exposed areas, small-sized domains with 5.3 μm spacing occasionally appeared, whereas irradiation allowed small domains in the order of 520 nm width to be generated. It has to be noted that these small domains are most probably surface domains that do not extend through the entire crystal, however, their depth is larger than 500 nm as can be concluded from the PFM images showing the same contrast as bulk domains [16].…”

“…Note that the apparently blurred, round shape of the domain in Fig. 4(a) is not due to an insufficient resolution of the instrument-the lateral resolution was 75 nm as determined by scanning across a domain wall in a standard PPLN sample [16] prior to the poling experiments-but represents accurate data. This measurement was repeated after finishing all poling experiments thereby confirming no changes in the tip radius during the series of measurements.…”

“…The samples were mounted onto an aluminum heat sink using heat conductive paste. The ion beam was shaped by a graphite slit with dimensions of 2 × 8 mm 2 ; a total ion current of 60 nA yields an ion fluence per second of 1.7×10 16 ions/m 2 s. Typical irradiation treatments lasted between 20 and 70 min. The irradiated area was located in the center of the z-surface of the crystal.…”

Epitaxial strain and electric boundary condition effects on the structural and ferroelectric properties of BiFeO3films

“…The stripe periodicity is ≈140 nm in case of a DyScO 3 substrate, whereas on GdScO 3 and SmScO 3 substrates the stripes are much finer, some of them even with a width of less than 10 nm, which is the limit of lateral resolution for PFM. 24 As a result the PFM signal is very low and the domain shape can not be resolved in detail.…”

Low-voltage nanodomain writing in He-implanted lithium niobate crystals

“…Moreover simple resolution issues of PFM imaging impede precise mapping of the domains geometry; thus the lateral resolution with the tips used here (radius 50-70 nm) is limited to ∼ 75 nm [23]. In addition, the depth of the domains can be estimated from the PFM contrast when compared to images recorded on a reference sample with bulk domains (PPLN) [12].…”