Synchrotron-radiation X-ray topography and reticulography of bulk $\beta$-Ga$_2$O$_3$ crystals grown by the cold crucible method

Yongzhao Yao; Koki Mizuno; Kazuki Ohnishi; Yukari Ishikawa; Masanori Kitahara; Taketoshi Tomida; Rikito Murakami; Vladimir Kochurikhin; Liudmila Gushchina; Kei Kamada; Koichi Kakimoto; Akira Yoshikawa

arXiv · 2603.14751

Synchrotron-radiation X-ray topography and reticulography of bulk $\beta$-Ga$_2$O$_3$ crystals grown by the cold crucible method

Yongzhao Yao·Koki Mizuno·Kazuki Ohnishi·Yukari Ishikawa·Masanori Kitahara·Taketoshi Tomida·Rikito Murakami·Vladimir Kochurikhin·Liudmila Gushchina·Kei Kamada·Koichi Kakimoto·Akira Yoshikawa

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Abstract

The structural properties of a $\beta$-Ga$_2$O$_3$ single crystal grown by the oxide crystal growth from cold crucible (OCCC) method were investigated using synchrotron radiation X-ray topography and X-ray reticulography. The region grown beneath the seed exhibits high crystalline quality with a rocking curve full width at half maximum of about 26 arcsec. During diameter enlargement, a twist-type lattice misorientation develops between the central and laterally expanded regions, originating near the shoulder and propagating along boundaries parallel to the $\langle010\rangle$ growth direction. Dislocation analysis reveals that $\langle010\rangle$-oriented screw dislocations dominate the defect structure with densities of ~$10^{5}$cm$^{-2}$, while higher densities (~$10^{6}$cm$^{-2}$) appear in the wing region. These results clarify defect formation in OCCC-grown $\beta$-Ga$_2$O$_3$ and provide insights for optimizing growth conditions.

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Yongzhao Yao, Koki Mizuno, Kazuki Ohnishi, Yukari Ishikawa, Masanori Kitahara, Taketoshi Tomida, Rikito Murakami, Vladimir Kochurikhin, Liudmila Gushchina, Kei Kamada, Koichi Kakimoto, Akira Yoshikawa. 2026-03-16. Synchrotron-radiation X-ray topography and reticulography of bulk $\beta$-Ga$_2$O$_3$ crystals grown by the cold crucible method. https://arxiv.org/abs/2603.14751

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