CuBr2(C10H8N2) - S=1/2 Two-Dimensional Rectangular Heisenberg Antiferromagnet

Magnetic susceptibility and X-band electron spin resonance study of a two-dimensional Heisenberg antiferromagnetic system CuBr2(bipy), where bipy = C10H8N2 is 4,4'-hipyridyl, has been performed in the temperature range from 300 K down to 2 K A rhombic anisotropy of the g-factor was obtained from X-band EPR measurements with g(x) = 2 037, g(y) = 2 100 and g(z) = 2 219 The temperature dependence of the magnetic susceptibility with a round maximum observed at 28 K suggests antiferromagnetic type of short-range order No signature of the magnetic long-range order in studied compound was observed The comparison of the magnetic susceptibility data with a two-dimensional rectangular Heisenberg model yields the values of intralayer exchange couplings J/k(B) = -47 K and J'/k(B) = -9 4 K