Crystallization kinetics of lithium niobate glass: determination of the Johnson–Mehl–Avrami–Kolmogorov parameters

Abstract

The formation of crystalline LiNbO3 (LN) from LN glass has been studied by means of differential scanning calorimetry and in situ synchrotron X-ray diffraction. The LN glass with no glass former was prepared by the polymerized complex method. The isothermal kinetics of the crystallization process is described using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation and the Avrami exponent n is found to be ~2.0, indicating that the crystallization mechanism is diffusion-controlled growth with a decreasing nucleation rate. The effective activation energy of crystallization calculated from isothermal measurements is 6.51 eV. It is found that the LN glass directly transforms into a rhombohedral LN crystal without any intermediate crystalline phase and most crystal grains are confined within the size of ~40 nm irrespective of different isothermal temperatures. Application of JMAK theory to the non-isothermal thermoanalytical study of crystallization of LN glass is discussed.

Ultrafast kinetics of the antiferromagnetic-ferromagnetic phase transition in FeRh

“…28 , pp. 16–21) 29 , 30 , Here is the Heaviside-step-function and is the latency where before there is no Δ E signal. After , the growth of the Δ E signal is determined by .…”

Relationship between Johnson–Mehl–Avrami and Šesták–Berggren models in the kinetics of crystallization in amorphous materials

“…(17) can be tested in the crystallization kinetics of glass components, polymer melts and other amorphous materials, as shown here [18][19][20][21][22][23][24][25].…”

Kinetics of crystalline nuclei growth in glassy systems

“…Moreover, extremely small sizes and low concentrations of the nascent crystalline nuclei as well as very low rates of crystal nucleation and of crystal growth complicate the study of the initial regimes of the crystallization in glasses by conventional experimental methods. Thus, if the growth of crystalline clusters in supercooled fluids at low and moderate levels of metastability is sufficiently well-studied subject, then there are still many disputed issues related with the structural ordering in glasses [2,[7][8][9][10][11][12][13]. Remarkably, the techniques based on molecular dynamics simulations appear here to be fruitful to elucidate microscopic mechanisms of initial stages of nucleation and growth processes for such the thermodynamic conditions where experimental methods have difficulties [1,[14][15][16][17][18][19].…”