Document Type


Subject Area(s)



Sr3CuPtxIr1-xO6 has been cited as an example of a one-dimensional quantum spin chain with competing ferromagnetic and antiferromagnetic interactions. We have measured the ac susceptibility of Sr3CuPtxIr1-xO6 with x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and 0.7, in magnetic fields of 0–60 kOe, and at temperatures down to 0.275 K. Our data show that the x=endpoint Sr3CuIrO6, exhibits long-range ferromagnetic order at T=20.1 K, contrary to results from dc susceptibility studies which indicated that it remained a one-dimensional ferromagnet to below 4 K. When platinum is substituted for iridium, antiferromagnetic couplings are introduced, and the susceptibility shows a diminishing signature of the three-dimensional ferromagnetic transition. Furthermore, the low-temperature susceptibility exhibits peaks which appear and evolve as x is increased. These results lead to a rich phase diagram in temperature and Pt concentration space. We find that the behavior of Sr3CuPtxIr1-xO6 cannot be simply described by the random quantum spin chain theories that were developed, in part, to address this system.

Included in

Chemistry Commons