resumo
Detection of dynamic surface displacements associated with local changes in material strain provides access to a number of phenomena and material properties. Contact resonance-enhanced methods of atomic force microscopy (AFM) have been shown capable of detecting similar to 1-3 pm-level surface displacements, an approach used in techniques such as piezoresponse force microscopy, atomic force acoustic microscopy, and ultrasonic force microscopy. Here, based on an analytical model of AFM cantilever vibrations, we demonstrate a guideline to quantify surface displacements with high accuracy by taking into account the cantilever shape at the first resonant contact mode, depending on the tip-sample contact stiffness. The approach has been experimentally verified and further developed for piezoresponse force microscopy (PFM) using well-defined ferroelectric materials. These results open up a way to accurate and precise measurements of surface displacement as well as piezoelectric constants at the pm-scale with nanometer spatial resolution and will allow avoiding erroneous data interpretations and measurement artifacts. This analysis is directly applicable to all cantilever-resonance-based scanning probe microscopy (SPM) techniques.
palavras-chave
SCANNING PROBE MICROSCOPY; FERROELECTRIC THIN-FILMS; ACOUSTIC MICROSCOPY; PIEZOELECTRIC COEFFICIENT; CONTACT ELECTRIFICATION; NANOMETER RESOLUTION; YOUNGS MODULUS; ELECTRIC-FIELD; NANOSCALE; SPECTROSCOPY
categoria
Science & Technology - Other Topics; Materials Science; Physics
autores
Balke, N; Jesse, S; Yu, P; Carmichael, B; Kalinin, SV; Tselev, A
nossos autores
Alexander Tselev
Investigador Principalagradecimentos
Experiments were planned and conducted through support provided by the US Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division through the Office of Science Early Career Research Program (NB). The facilities to perform the experiments were provided at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy, which also provided additional support for simulation of cantilever dynamics and advanced data analysis (SJ, BC, SVK, AT). PY provided the ferroelectric PZT sample with support from the National Basic Research Program of China (Grant No. 2015CB921700) and National Natural Science Foundation of China (Grand No. 11274194).