Abstract
The magnetic susceptibility and magnetization of two layered Heisenberg antiferromagnets with moderate exchange are reported. The two isostructural compounds, and contain Cu(II) ions related by C centering, yielding four equivalent nearest neighbors. The crystal structure of the synthesized compound, shows the existence of layers of distorted copper(II)-bromide tetrahedra parallel to the plane, separated by the organic cations along the c axis. Magnetic pathways are available through the bromide-bromide contacts within the layers and provide for moderate antiferromagnetic exchange. Susceptibility measurements indicate interaction strengths to be 8.5(2) K and 6.5(2) K and ordering temperatures of 5.1(2) K and 3.8(2) K for and respectively. High-field magnetization experiments on both compounds show upward curvature of Magnetization measurements made at show saturation occurs in at 18.8 T and in at 24.1 T. The magnetization curves are consistent with recent theoretical predictions. Single-crystal magnetization measured at 2.0 K indicates a spin-flop transition at 0.38 T and 0.63 T for and respectively.
- Received 22 August 2001
DOI:https://doi.org/10.1103/PhysRevB.65.144412
©2002 American Physical Society