  Recently it has been shown that the modules and phase of complex reflection
coefficient can be determined by using a magnetic substrate and polarized
neutrons. Several other methods have also been worked out based on measurement
of polarizations of reflected neutrons from magnetic reference layers and
magnetic substrate. However, due to the fact that available reflectometers are
limited in the choice of polarization of reflected beam in the same direction
as the polarization of the incident beam, neither of the methods which are
based on polarization analysis, has been proven to be experimentally practical.
In this paper, we have proposed a new method for determining the phase of
reflection coefficient which is based on two measurements of polarization which
correspond to two magnetic fields with the same magnitudes and different
orientations. The polarization analysis is performed in the same direction as
the polarization of the incident beam and is well suited for available
reflectometers. The problems envisaged in implementation of the method are also
discussed.
