Role of ion beam excitations on quasi one-dimensional magnetic system of Mn-doped LiCuVO₄

Induction of short range ferromagnetic ordering has been observed in the quasi one dimensional antiferromagnetic LiCuVO₄ system with doping of Mn in the octahedral (Cu) site. Though, magnetic ordering is not stable enough as further increase of Mn-concentration, magnetic ordering gets deteriorated. This might be the case that Mn²⁺ ions, with strong magnetic moment as compared to Cu²⁺ ions, enhance the ferromagnetic coupling between the nearest neighbor atoms of quasi-one-dimensional magnetic LiCuVO₄ system. Ferromagnetic ordering in LiCu_0.95Mn_0.05VO₄ system also degraded after high energy ion beam excitation which creates defects and may disturb the short range ferromagnetic ordering in its near locality but it does not have much effect on the long range antiferromagnetic ordering. Irradiation causes no change in Raman modes of LiCu_0.95Mn_0.05VO₄ system, while it produces some new vibrational modes in intermediate and high frequency region of LiCu_0.9Mn_0.1VO₄ system. Above results have been understood based on competitions between ferromagnetic nearest neighbor (NN) coupling and antiferromagnetic next nearest neighbor (NNN) coupling in CuO₂ chain. - Highlights: • Quasi 1-D magnetic systems LiCu_1-xMn_xVO₄ (x = 0.00, 0.05 & 0.10) have been prepared. • Doping of Mn induces short range ferromagnetic ordering in the system. • High-energy ion beam excitations degrade ferromagnetic ordering in Mn doped LiCuVO₄. • Irradiations decay short range FM order but has no effect on long range AFM order. • Irradiation leads to few new vibrational modes in LiCu_0.9Mn_0.1VO₄ system