MAGNETIC-PROPERTIES OF OXYGEN PHYSISORBED IN CU-TRANS-1,4-CYCLOHEXANEDICARBOXYLIC ACID

Magnetic properties of oxygen physisorbed in Cu-trans-1,4-cyclohexaned icarboxylic acid having one-dimensional micropores are studied. O-2 is well known as a magnetic molecule with S=1. In the case of the low ad sorption, temperature dependence of the susceptibility shows the Schot tky-type broad peak and the high-field magnetization process has a ste p at around 34T with saturation moment of 2 mu(B)/O-2. These results a re interpreted by the dimer model of S=1/2 with an antiferromagnetic e xchange interaction. Broadening of the step of magnetization with incr easing the adsorption may be due to the interdimer interaction or the distribution of the intra-dimer exchange interaction. Linear magnetiza tion process which is characteristic of one-dimensional Heisenberg ant iferromagnet has not been observed even in the full pore region.