Changes in structural and dielectric properties of nontronite caused by heating

The study was focused on changes in the electrical and structural parameters of nontronite as a function of temperature in the range of 25 degrees C-325 degrees C. Nontronite during heating loses water from the interlayer space. Structural changes in the mineral were monitored by X-ray powder diffraction, thermal analysis, and dielectric spectroscopy. The experiments showed that between 35 degrees C-60 degrees C the mineral loses only a small part of water bound between the layers. This resulted in a significant change in the distance between the layers from 15.2 angstrom to 13.0 angstrom and a 100% increase in low-frequency electric permittivity. The main process of losing interlayer water molecules starts at 60 degrees C and finishes close to 160 degrees C. Interlayer water responds to the external electric field, causing an increase in electric permittivity. Analysis of dielectric relaxation gave valuable insight into the dynamics of weakly bound interlayer molecules-water in the case of natural nontronite.

Automated summary

The study focused on the changes in electrical and structural parameters of nontronite with temperature variations from 25 degrees C to 325 degrees C. Heating causes nontronite to lose water from the interlayer space, leading to significant structural alterations. The experiments showed that the mineral loses only a small part of water between the layers at 35-60 degrees C, resulting in changes in interlayer distance and electric permittivity. The main process of losing interlayer water molecules starts at 60 degrees C and finishes close to 160 degrees C.