ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Ferrous trimethylammonium chloride (FeTAC) is a member of a family of compounds that consist of chains of bihalide-bridged metal ions aligned along the b axis of the orthorhombic unit cell. The chains are connected in (bc) planes by hydrogen bonding of the waters of hydration; these planes are isolated along the a axis by the large trimethylammonium groups. FeTAC orders three dimensionally below TN=3.16 K, with the moments, which are canted from the b axis by ∼20°, coupled ferromagnetically along the b axis and staggered along the [101] direction. The order parameter follows the exact Onsager solution for a rectangular 2D Ising lattice below T/TN≈0.95, with ratio for the two in-plane magnetic exchange constants of 1.3×10−3. However, quasielastic scattering measurements in the vicinity of TN show that the correlations do not evolve as do those of the 2D Ising antiferromagnets ErBa2Cu3O7 and K2CoF4. Above TN, magnetic excitations along the b axis that follow the dispersion relation of a 1D ferromagnet with a gap of 3.7 meV have been observed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.353476
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