Effect of doping in BaNi2V2O8, a two-dimensional honeycomb antiferromagnet

We report the temperature dependence of susceptibility χ(T) of the two-dimensional (2D) honeycomb antiferromagnetic (AF) Ba(Ni1-xCux)2V2O8 for x=0.0,0.05 and 0.1. The undoped BaNi2V2O8 is known to exhibit long-range-order (LRO) below TN∼50K with J/kB=48K. We find that doping Cu (S=1/2) at Ni (S=1) site results in a magnetic dilution effect which suppresses the three-dimensional (3D) ordering temperature (TN). Our results are compared with those of nonmagnetic Mg-doped BaNi2V2O8.