The results of a study of composites obtained by mixing potassium nitrate and carbon nanotubes are discussed. It has been shown that the effects of the interaction of the composite components lead to the expansion of the temperature range of the existence of the ferroelectric phase of potassium nitrate from 22 K for KNO3 to 38 K for a composite with a carbon nanotubes content of 2.0 vol % percent.