Magnetic susceptibility for CaV4O9

We examine experimental magnetic susceptibility chi(tot)(T) for CaV4O9 by fitting with fitting function alpha chi(mag)(T) + c. The function chi(mag)(T) is a power series of 1/T and the lowest order term is fixed as C/T, where C is the Curie constant as determined by the experimental g-value (g = 1.96). Fitting parameters are alpha, c and expansion coefficients except for the first one in chi(mag) (T). We determine alpha and c as alpha similar or equal to 0.73 and c similar or equal to 0 for an experimental sample. We interpret a as the a volume fraction of CaV4O9 in the sample and chi(mag)(T) as the susceptibility for the pure CaV4O9. The result of alpha not equal 1 means that the sample includes nonmagnetic components. This interpretation consists with the result of a perturbation theory and a neutron scattering experiment.