Effects of Impurities in Quasi-One-Dimensional S=1 Antiferromagnets

For the weakly coupled S=1 antiferromagnetic Heisenberg chains on a simple cubic lattice, the effects of magnetic impurities are investigated by the quantum Monte Carlo method with the continuous-time loop algorithm. The transition temperatures of the impurity-induced phase transitions for magnetic impurities with S=1/2, 3/2, and 2 are determined and compared with the transition temperature induced by the non-magnetic impurities. Implications on the experimental results are discussed.