https://doi.org/10.1140/epjb/e2012-30200-6
Regular Article
Theoretical analysis of neutron scattering results for quasi-two dimensional ferromagnets
S N Bose National Centre for Basic Sciences, Block-
JD, Sector- III, Salt Lake, 700098
Kolkata,
India
a e-mail: sbhjt72@gmail.com
Received:
6
March
2012
Received in final form:
9
July
2012
Published online:
22
November
2012
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-
ferromagnetic material K2CuF4.
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-, show occurence 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.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2012
