Practical aspects and implications of interfaces in glass-ceramics: a review

Abstract

Practical aspects and implications of interfaces in glass-ceramics: a reviewGlass-ceramics, prepared from the crystallization of interface-free, homogeneous glass, offer a unique perspective to study the influence of interfaces owing to the controlled manner in which interfaces (grain boundaries) can be introduced into the material. This review begins by considering the kinetics of interface development, itself strongly influenced by surface energetics. We then take up mechanical properties, the increase of which over that of their glassy precursors remains a cornerstone of what makes glass-ceramics desirable. Here, the role of the interface, both between crystals and, in some cases, within crystals (e. g., twin planes), serve to provide multiple ways in which to produce tough and strong materials. Hermetic crystal -glass interfaces are probably the rule in most glass-ceramics, rather than the exception, and are well demonstrated by several systems. Crystal clamping -the process by which crystals surrounded by residual glass in a glass-ceramic undergo stress due to coefficient of thermal expansion mismatches or by the inability of the crystal to go through a polymorphic transition upon cooling -has now been demonstrated in a number of studies with calculated stresses reaching 1 GPa. Electrical property studies of multi-phase glass-ceramics have shown the wide variety of phenomena possible with these materials, although more detailed studies will be necessary to fully understand the complex interplay between crystals, grain boundaries, space-charge regions, and residual glass. Light scattering is one of the more important implications of interfaces in glass-ceramics and quantitative approaches are more and more used to characterize this often unwanted feature. Concluding this review, we attempt to address four key questions that seek to extract those features of interfaces in glass-ceramics that have been application-enabling, require additional understanding and, finally, which might point a way towards new applications in the future.

Impedance Spectroscopy Studies of Fresnoites in BaO–TiO2–SiO2 System

“…Glass ceramics find applications as dielectrics, pyroelectrics and piezoelectrics, and recently as high temperature and high energy density capacitors 7,8 . One of their main advantages is that excellent microstructural control and low porosity can be obtained over a broad range of crystalline and amorphous phase volume fractions 9 …”

“…7,8 One of their main advantages is that excellent microstructural control and low porosity can be obtained over a broad range of crystalline and amorphous phase volume fractions. 9 Impedance spectroscopy is particularly advantageous to study ferroelectric ceramics such as barium titanate because they exhibit temperature dependent permittivity and show Curie point transition between the ferroelectric and the paraelectric states. 2 Therefore, it is straightforward to distinguish between ferroelectric grains and nonferroelectric regions such as grain boundaries and variations in electrical properties of those two different regions can be characterized.…”

Piezoelectric glass‐ceramics: Crystal chemistry, orientation mechanisms, and emerging applications

“…Glass‐ceramics offer the opportunity to incorporate unique crystalline properties within a liquid‐formable matrix. They share attributes of both glasses and ceramics while maintaining certain advantages over classically prepared ceramics, including easy liquid‐state formability 1 . Discovered accidentally by S. Donald Stookey in 1953, glass‐ceramics have since emerged in applications including heat‐resistant tableware and cookware, nozzle cones for missiles, and dental implants 2,3 .…”

“…2,3 While glass-ceramics have been explored widely for their thermal stability and mechanical properties, they also offer unique symmetry-dependent properties such as piezoelectricity, pyroelectricity, and second harmonic generation. 1 It is important to note that all polar materials (or pyroelectric materials) are piezoelectric, but not all piezoelectric symmetries are pyroelectric. It is these symmetry-dependent properties that are traditionally forbidden in a glassy material that offer novel applications for glass-ceramics in lasers, non-linear optical devices, sensors, and actuators, provided there is a method to create the appropriate symmetry condition.…”

Construction and characterization of phenol-based sensor derived from colloidal chemistry

“…The particle size of the sol and gel can be adjusted in the fabrication processes to range from 1 nm to 1 m. The actual composition and size is dependent upon the final usage of the sol-gel system [44]. The application of sol-gel is in many fields such as thin films [45], dense ceramic or glass materials [46], optical ceramic fibers [47], powders [48]. These constructs can be used in coatings, constructional materials or biomedical applications [49].…”