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Ga₂O₃ is doped with Fe to make it semi-insulating [1]. We have annealed Ga₂O₃:Fe samples obtained from the Tamura Corp. in D₂ at elevated temperatures. This treatment produces an O-D vibrational line at 2578 cm^-1 that has not been seen previously in deuterated Ga₂O₃ samples not containing Fe [2]. A treatment in a mixture of H₂ and D₂ produces an additional line at 2585 cm^-1 suggesting that this O-D center contains two identical D atoms. One of the coupled O-D modes is allowed, and a second is forbidden, similar to the V_Ga(1) -2D center studied previously [3]. Centers containing both H and D give an additional dynamically decoupled mode. These results provide evidence for an Fe-(OD)₂ complex in semi-insulating Ga₂O₃.

[1] A. Y. Polykov et al., Appl. Phys. Lett. 113, 142102 (2018).
[2] Y. Qin et al., ECS J. Solid State Sci. Technol. 8, Q3103 (2019).
[3] P. Weiser et al., Appl. Phys. Lett. 112, 232104 (2018).