Spontaneous magnetization of dense neutron matter and electron-positron plasma

It is shown that dense degenerate neutron gas can undergo transition to a magnetically ordered state, and this one is a phase transition of the second order. It is also shown that the occurrence of the spontaneous magnetization explains the characteristic value of the neutron star (pulsar) density and magnetic field. The problem of the occurrence of spontaneous magnetization in dense electron-positron plasma is studied also.