Dipole moment and spontaneous polarization of ferroelectric nanoparticles in a nonpolar fluid suspension

Stressed ferroelectric nanoparticles, less than 10 nm in diameter, are investigated in a nonpolar fluid. Measuring ferroelectric properties of the smallest achieved BaTiO₃ ferroelectric nanoparticles allows for the determination of dipole moment and spontaneous polarization as a function of size and concentration; the results are significantly greater than in bulk BaTiO₃. This is achieved by using a direct measurement of the displacement current density and either integrating over half a period or fitting the experimental results using the derivative of the Langevin function.