Ion mobility and thermal properties of glasses in the BiF3–LiF and BiF3–LiF–ZrF4 systems

Ion mobility and the characteristic temperatures of bismuth fluoride glasses in the BiF3–LiF and BiF3–LiF–ZrF4 systems were studied by Nuclear Magnetic Resonance and Differential Scanning Calorimetry methods. Analysis of 7Li and 19F Nuclear Magnetic Resonance spectra made it possible to reveal the character of ion motion in the fluoride and lithium sublattices of the glasses under temperature variation, and to determine the types and temperature ranges in which they took place. It was found that the main types of ion motion in the glasses were the diffusion of lithium ions and the reorientation of fluorine-containing groups. The diffusion of fluorine ions was observed only in crystallized glasses.

► The NMR spectrum shape was associated with the nature of ion motion in the glasses. ► With increased temperature, the transition to diffusion of Li+ ions was observed. ► The diffusion of F− ions was observed only in the crystallized glasses. ► A relationship was found between composition and glass characteristic temperatures. ► Application of these glasses is offered for the development of functional materials.