An electronic device in the form a two-dimensional array of nanopillars extending generally normal to a substrate is provided. The nanopillars are made from a paraelectric or superparaelectric material. In addition, a linear dielectric medium is located between individual nanopillars. A two-dimensional array of paraelectric or superparaelectric nanopillars and a linear dielectric medium form the effective dielectric medium of a paraelectric or superparaelectric varactor. In some instances, the nanopillars are cylindrical nanopillars that have an average diameter and/or average height/length between 1-300 nanometers. In other instances, the nanopillars are quasi-nanoparticles that form self-aligned nano-junctions. In addition, each of the nanopillars has a single paraelectric or superparaelectric dipole domain therewithin. As such, each of the nanopillars can be void of crystallographic defects, polycrystallinity, interactions between ferroic domains, and defects due to ferroic domain walls.