MAGNETIC-SUSCEPTIBILITY OF NDGAO3 AT LOW-TEMPERATURES - A QUASI-2-DIMENSIONAL ISING BEHAVIOR

The ac magnetic susceptibility of a NdGaO3 single crystal has been mea sured along the three principal crystallographic axes in the temperatu re range from 50 K down to 0.07 K. The data obtained indicate that the compound orders antiferromagnetically at T-N approximate to 1 K with the sublattice moments parallel to [001], which is consistent with ear lier neutron-diffraction results. The data are interpreted in terms of the Ising model on the simple tetragonal lattice in the quasi-two-dim ensional regime: the intralayer exchange is relatively strong and anti ferromagnetic, J(perpendicular to)/k = -0.70 K, whereas the interlayer exchange is ferromagnetic and an order of magnitude weaker, J(paralle l to)/k = 0.07 K. This model also describes well the earlier specific- hear data. The g factors deduced from the low-temperature susceptibili ty, g(x) = 1.84, g(y) = 2.41, g(z) = 2.73, are in reasonable agreement with electron paramagnetic resonance measurements on Nd-doped LaGaO3. (C) [S0163-1829(98)02625-3].