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

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 $K_{2}Cu{F}_4$. 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.

16 pages, 6 figures, 1 Table Submitted for publication

References in corpus (6)

• Magnetic correlations in La2-xSrxCoO4 studied by neutron scattering : possible evidence for stripe phases
• Locallized Magnetism in Low-Dimensional Systems
• Magnetic order and spin fluctuations in low-dimensional insulating systems
• Magnetic excitations in multiferroic LuMnO3 studied by inelastic neutron scattering
• Spin-wave excitations in the ferromagnetic-metallic and in the charge, orbital and spin ordered states in Nd${}_{1-x}$Sr${}_x$MnO${}_3$ with x$\approx$0.5
• Response of acoustic phonons to charge and orbital order in the 50\% doped bilayer manganite LaSr${}_2$Mn${}_2$O${}_7$

Cited by in corpus (2)

• The connection between vortex-like topological excitations and conventional excitations in quantum ferromagnetic spin systems on two dimensional lattice and their stability
• Semi-phenomenological analysis of neutron scattering results for quasi-two dimensional quantum anti-ferromagnet