Inelastic neutron scattering study of magnetic excitations of 2D layered honeycomb compounds Pr2Pt6Al15 and Nd2Pt6Ga15

The rare earth intermetallic compounds are well known for their diverse magnetic properties and electronic ground states which are determined by to the competing Kondo, RKKY, crystal electric field and spin-orbit interactions. Ternary intermetallic compounds Pr2Pt6Al15 and Nd2Pt6Ga15, having a monoclinic superstructure, present interesting magnetic properties. The structure consists of a honeycomb like arrangement formed by the Pr1/Nd1 and Pr2/Nd2 atoms and at centre Al3/Ga3-triangles. The magnetic measurements on both the compounds reveal occurrence of long range magnetic ordering of complex nature below 13 K in Pr2Pt6Al15 and below 11 K in Nd2Pt6Ga15. Moreover, the χ(T) data show irreversibility between the ZFC and FC data, and in ordered state, the M(H) isotherms show metamagnetic behaviour with hysteresis which depicts the interplay of antiferromagnetic and ferromagnetic correlations. Further investigations using the inelastic neutron scattering experiment are highly desired to understand the magnetic ground state and determine the crystal field states of these compounds. We propose to carry inelastic neutron scattering measurements on Pr2Pt6Al15 and Nd2Pt6Ga15 using MERLIN spectrometer to determine the crystal field level scheme and investigate spin wave excitations.