HIGH TEMPERATURE SERIES ANALYSIS OF SUSCEPTIBILITY DATA OF La2CuO4

The zero-field magnetic susceptibility of La2CuO4 is analyzed using high temperature series for five different magnetic Hamiltonians in two-dimensions: spin 1/2 Heisenberg model, spin 1/2 XY model, classical Heisenberg model, classical XY model, and the Ising model. The goodness of fit indicates that the quantum spin 1/2 Heisenberg model is best, with the classical XY model second.