Phase diagram of two-dimensional electron gas in a perpendicular magnetic field around Landau level filling factors ν=1 and 3

The measured melting curve Tm(ν) between the crystal and liquid phases is analyzed using thermodynamics to extract the change of magnetization ΔM as a function of the Landau level filling factor ν, near ν=1. An explanation of ΔM(ν) is proposed in terms of skyrmions. Near ν=3, a Wigner crystal is the most probable solid phase, experiments excluding skyrmions.