This paper presents an approach to solving the phase problem in neutron reflectometry (including polarized neutron reflectometry) based on the effect of the resonant interaction of nuclei of gadolinium isotopes 155Gd and 157Gd with thermal neutrons. This effect is used to implement the reference-layer method, which allows one, based on the results of three experiments, to calculate the complex reflection coefficient of the sample under study. Knowing the complex reflection coefficient makes possible model-independent analysis of the interaction potential, both nuclear and magnetic. The main application of this approach is the study of the structure of layers and interfaces, as well as determination of the magnetic state of multilayer metal nanoheterostructures. The theoretical basis of this method is given, which consists in deposition onto the studied sample of a gadolinium layer with known parameters, one of which can be varied in a controlled manner. The scheme of the experiment is described in detail using model numerical calculations. An experimental result is given for a simple single-layer niobium sample, for which the modulus and phase of the reflection coefficient are calculated. Promising directions for improving the method and possible directions for further work are proposed. Expectations for the characteristics of a compact neutron source, which are necessary for optimal implementation of the proposed method, are formulated. © 2023, Pleiades Publishing, Ltd.