The dualism of matter is
inherent in the de Broglie relation which contains a wave concept
(l) and a particle concept (p) The de Broglie wavelength is
independent of the charge and nature of the material  particle It is
significantly measurable (of the order of the atomic-planes spacing
in crystals) only in case of sub-atomic particles like electrons,
protons, etc (due to smallness of their masses and hence, momenta)