Carrasco Madrigal , DanielDolado, J.Pérez Peinado, PaulaRodríguez Fernández, BeatrizAlonso Orts, ManuelSan Juan, J. M.Nó, M. L.Hidalgo Alcalde, PedroMartínez-Criado, G.Méndez Martín, María BianchiNogales Díaz, Emilio2025-07-092025-07-092025-04-01D. Carrasco, J. Dolado, P. Pérez-Peinado, B. Rodríguez, M. Alonso-Orts, J.M. San Juan, M.L. Nó, P. Hidalgo, G. Martínez-Criado, B. Méndez, and E. Nogales, “β-Ga2O3:Cr nanowires with optical microcavities for determining local heating induced by x-ray nanobeams,” APL Materials 13(4), 041115 (2025).10.1063/5.0261501https://hdl.handle.net/20.500.14352/122375©Author(s) 2025 INST 144/462-1 FUGG ZF04/2021This study explores the x-ray excited optical luminescence (XEOL) of optical microcavities fabricated in β-Ga2O3:Cr nanowires (NWs). XEOL measurements reveal prominent luminescence bands in the near ultraviolet-blue (NUV-B) and in the red-near infrared (R-NIR) spectral regions. The NUV-B emission originates from β-Ga2O3 defects, while the R-NIR band is attributed to Cr3+ intraionic transitions. Both spectral regions exhibit sharp resonances, which are analyzed as Fabry–Pérot and whispering gallery mode resonances. Exposure to x-ray nanobeam induces a redshift of the sharp R-NIR peaks, attributed to local temperature increase in the NWs caused by x-ray absorption. The influence of this temperature rise on the NUV-B peaks is also evaluated. In addition, the local temperature increase due to x-ray absorption is estimated through COMSOL finite-difference time-domain simulations, incorporating the material’s physical and thermal properties. This work demonstrates the application of β-Ga2O3:Cr optical microcavities as luminescence-based nanothermometers to probe the localized effects of x-ray nanobeam irradiation.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article2166-532Xhttps://doi.org/10.1063/5.0261501https://pubs.aip.org/aip/apm/article/13/4/041115/3344426/Ga2O3-Cr-nanowires-with-optical-microcavities-foropen access538.9LuminiscenceFísica de materiales2211 Física del Estado Sólido