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arXiv · 1203.3069

Theoretical analysis of neutron scattering results for quasi-two dimensional ferromagnets

Subhajit Sarkar·Samir K. Paul·Ranjan Chaudhury
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Abstract

A theoretical study has been carried out to analyse the available results from the inelastic neutron scattering experiment performed on a quasi-two dimensional spin-1/2 ferromagnetic material $K_2CuF_4$. Our formalism is based on a conventional semi-classical like treatment involving a model of an ideal gas of vortices/anti-vortices corresponding to an anisotropic XY Heisenberg ferromagnet on a square lattice. The results for dynamical structure functions for our model corresponding to spin-1/2, show occurrence of negative values in a large range of energy transfer even encompassing the experimental range, when convoluted with a realistic spectral window function. This result indicates failure of the conventional theoretical framework to be applicable to the experimental situation corresponding to low spin systems. A full quantum formalism seems essential for treating such systems.

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Subhajit Sarkar, Samir K. Paul, Ranjan Chaudhury. 2012-03-14. Theoretical analysis of neutron scattering results for quasi-two dimensional ferromagnets. https://doi.org/10.1140/epjb/e2012-30200-6

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