Graphene is the single layer of honeycomb-shaped carbon network, for which 2010 Nobel Prize in Physics was awarded thanks to its novel electronic properties. One of such novelties is the particles carrying an electrical charge but zero mass. In this work, we are going to investigate the quantum particles carrying magnetic field but zero charges on magnetic materials that have similar structures as graphene, namely CrI3 and Cr2Ge2Te6. In them, magnetic moments of Cr3+ ions align on honeycomb-shaped lattices and produce these "magnons" via cooperative oscillations. We will use inelastic neutron scattering method to observe the energy of such magnons as a function of neutron momentum transfer. We will be then able to estimate the bonding strength between electronic magnetic moments by analyzing the spectra, which may eventually reveal the existence of such massless magnetic particles.