Investigation of EFM capabilities for probing interphases in nanodielectric materials: A numerical study

Interphases are usually considered to be responsible for the physical properties of nanocomposites unexplainable by general mixture laws. The prediction of the effective dielectric permittivity of nanodielectrics needs to consider the intrinsic dielectric permittivity of the interphase and its volume. However, no reliable experimental method has been yet developed in order to characterize the interphase at the nanoscale. This work aims at verifying via numerical simulations, the electrostatic force microscope (EFM) signal behavior, capabilities and limits, in order to detect and characterize nanoparticles and interphases present in nanodielectric materials. We showed at first the form of the EFM signal to be expected in front of a nanodielectric material. Then, we simulated the effect of the dimensions and the dielectric permittivities of the nanodielectric filler, interphase and matrix on the EFM signal. Consequences on the detectability and physical determination of the interphase using EFM were discussed.