Abstract
We report on pulsed-field magnetization, -band electron spin resonance (ESR), and NMR measurements of the spin triangle clusters ( and Sb). The pulsed-field magnetization shows pronounced hysteresis loops and magnetization steps including the half-step magnetization. The detailed magnetization behavior depends substantially on the diamagnetic heteroatom . The angular dependence of ESR parameters necessitates Dzyaloshinskii-Moriya interaction. The temperature dependence of the spin-lattice relaxation rate, , scales well to , where is the static susceptibility. The spin-spin relaxation rate, , increases rapidly for temperatures below due to dipolar interactions between the nuclei and spins. The two clusters exhibit a markedly different field dependence of at antilevel crossing points. The enhancement of is noticeable only for . Since the spin configurations of both clusters are nearly the same, the dependence of magnetization and on is ascribed to the strong coupling of the spins to a lattice vibration, leading to an enhanced mixing of the chiral state.
2 More- Received 20 August 2007
DOI:https://doi.org/10.1103/PhysRevB.77.024406
©2008 American Physical Society