Magnetic susceptibility χ (T) of a quasi-one-dimensional S = frac(1, 2) quantum spin system DMACuCl3 (DMA=(CH3)2NH2) has been measured in a magnetic field. This compound exhibits a unique magnetization curve M (H). M (H) rises with increasing magnetic field up to Hc 1 = 2 T, and shows a frac(1, 2) plateau between Hc 1 and Hc 2 = 3.5 T followed by a gradual increase to the saturation at Hs = 14 T. In the previous studies, the specific heat C (T) shows a sharp peak in the low field region for H ≤ Hc 1 and in the high field region for Hc 2 ≤ H [Y. Yoshida, O. Wada, Y. Inagaki, T. Asano, K. Takeo, T. Kawae, K. Takeda, Y. Ajiro, J. Phys. Soc. Japan 74 (2005) 2917. ]. The field dependence of the two peaks, however, is unusual in comparison with that in conventional quantum spin systems investigated so far. In χ (T), the antiferromagnetic ordering in H ≤ Hc 1 is observed, although its field dependence is inconsistent with that of C (T). The origin of the discrepancy in the two measurements is discussed.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics