High-Density Ice I[sub.h] Obtained by Crystallization of Water in a High-Frequency Electromagnetic Field

The processes of crystallization and melting, and the structure of ice formed under freezing in an alternating electromagnetic field with a frequency of 2.45 GHz have been studied using thermometry, differential scanning calorimetry, and X-ray diffraction. Using X-ray powder diffraction at 85 K, it was determined that the obtained samples consisted of several phases of hexagonal ice I[sub.h,] with a density 0.43 ÷ 2.58% higher than that of ordinary ice. The time necessary for this ice to crystallize was approximately 2.2 times shorter than that of ordinary ice not exposed to an alternating electromagnetic field. According to the data of differential scanning calorimetry, the melting of this ice was accompanied by an endothermic heat effect 9% greater than that of ordinary ice, and a melting point that was 1 °C lower. A similar effect is typical of the melting of metastable phases. We assume that the formation of ice I[sub.h] with increased density results from the action of an alternating electromagnetic field on the network of hydrogen bonds of liquid water which is a precursor for ice formation.