Investigation of ferroelectric phase transitions of water in nanoporous silicates in simultaneous electrical noise and calorimetric measurements

The phase transitions of water in the nanoporous silicate materials SBA-15 and MCM-41 with an ordered system of cylindrical pores have been investigated. Measurements of low-frequency electrical noises (Barkhausen noises) in the frequency range of 1–100 Hz have been performed simultaneously with relative calorimetric measurements. It has been found that the voltage of electrical fluctuations increases approximately 100 times in the temperature range from -30 to -50$^\circ$C, which is associated with the first-order and second-order ferroelectric phase transitions. It has been assumed that the ferroelectric ice XI can be formed in capillary pores of the materials under investigations.