Magnetic properties of NaNiFe$_2$(VO$_4$)$_3$ compound at low temperatures

In the low temperature region, a change in the magnetic state was detected in the new NaNiFe$_2$(VO$_4$)$_3$ magnetic compound, confirmed by the results of experimental study by gamma resonance and magnetometry methods. The formation of disordered magnetism in multicomponent vanadate is facilitated by the features of the crystal structure, in which magnetically active cations occupy several crystallographically non-equivalent mixed positions with uneven filling with iron and nickel ions.