Magnetic properties of S=1/2 two-dimensional quantum antiferromagnet Cu(D2O)2(C2H6D2N2)SO4

Specific heat and susceptibility measurements of Cu(D2O)2(C2H6D2N2)SO4 have been performed to investigate the influence of the partial deuteration on the magnetic properties of Cu(H2O)2(C2H8N2)SO4 — a representative of an S=1/2 spatially anisotropic triangular antiferromagnet with intralayer exchange coupling Jeff/kB≈1.5K. The analysis of experimental data at helium temperatures revealed a slight, less than 10% reduction of magnetic coupling as well as ordering temperature. The origin of the observed behavior is discussed.