# Kinetics studies on $\\kappa$ to $\\beta$-Ga$\_2$O$\_3$ phase transformations via in-situ high temperature X-ray diffraction Source: [Kinetics studies on $\\kappa$ to $\\beta$-Ga$\_2$O$\_3$ phase transformations via in-situ high temperature X-ray diffraction]() Collection index: [llms.txt]() Data updated: 2026-04-08T05:00:12.103Z Authors: Jingyu Tang, Po-Sen Tseng, Kunyao Jiang, Rachel C. Kurchin, Robert F. Davis, Lisa M. Porter Published: 2026-04-05T23:42:43.000Z ## Abstract The kinetics of the $\\kappa$ to $\\beta$-Ga$\_2$O$\_3$ phase transformation were investigated in five batches of nominally phase-pure $\\kappa$-Ga2O3 thin films heteroepitaxially grown on c-plane sapphire, with film thickness ranging from 700 to 1100 nm, using in-situ high-temperature X-ray diffraction. Phase fractions were quantitatively extracted through modified Rietveld refinement that accounts for preferred orientation, and the transformation kinetics were analyzed using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. The applicability of the JMAK model to thin-film materials was evaluated and its lower and upper bounds for thin films and bulk materials were established. Based on this analysis, a method specifically suited for thin-film kinetic studies was developed and yielded reproducible and robust results across all five sample batches. The results indicate that the $\\kappa$ to $\\beta$ phase transformation in ~700-1100 nm films is best described as an interface-controlled, site-saturated nucleation with thickness-limited or effectively two-dimensional growth. ## Recorded benchmark results A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage. ## Original sources and implementation [Original paper]() [PDF]()