Spin wave dispersion and magnons from short range order in tapiolite (FeTa2O6); a quasi-two-dimensional antiferromagnet

Hague, J. P.; Chung, E. M. L.; Visser, D.; Balakrishnan, G.; Clementyev, E.; Paul, D. McK. and Lees, M. R. (2005). Spin wave dispersion and magnons from short range order in tapiolite (FeTa2O6); a quasi-two-dimensional antiferromagnet. Journal of Physics: Condensed Matter, 17(46) pp. 7227–7235.

DOI: https://doi.org/10.1088/0953-8984/17/46/007

Abstract

We describe neutron inelastic scattering measurements of spin waves in the quasi-two-dimensional antiferromagnet FeTa2O6. The intrinsic spin wave dispersion for a single domain is deduced from linear spin wave theory and used to determine the intra-plane exchange coefficients. Almost dispersion-free excitations are observed along the c* direction perpendicular to the magnetic planes. This justifies the neglect of inter-plane coupling, which merely stabilizes the ordered configuration below TN. Spin wave theory yields values for the nearest neighbour and next nearest neighbour exchange constants on perpendicular diagonals of J = −0.040(9) meV, J'/J = 0.20(0), J''/J = 0.23(9), and the anisotropy parameter D = 0.31(8) meV. The large value of D shows an Ising-like spin configuration to be consistent with the experimental data. Measurements of the temperature dependence of the scattering show that magnetic excitations persist to at least 20 K (over two times TN) due to the extensive 2D short range order. This is a highly unusual result, and has consequences for the understanding of two-dimensional spin systems.

Viewing alternatives

Look up in Google Scholar

Metrics

Public Attention

Altmetrics from Altmetric

Number of Citations

Citations from Dimensions
No digital document available to download for this item

Item Actions

Export

About

CORE (COnnecting REpositories)

Recommendations