III Simposio de Postgrado 2025: Ingeniería, ciencia e innovación

11 171 Magnetron-Sputtered MAX/MXene Thin Films: A Bottom-Up Approach for Scalable Gas Sensing Applications Amit Kumar Gangwar ¹ , ²* Sana Munir ¹ , ² Roberto Villarroel ¹ , ³ Andreas Rosenkranz ¹ , ² Rodrigo Espinoza-González ¹ , ² ¹ ANID - Millenium Science Initiative, Millenium Nuclei of Advanced MXenes for Sustainable Applications (AMXSA), Santiago. Chile ² Departamento de Ingeniería Química, Biotecnología y Materiales, Facultad de Ciencias Fisicas y Matematicas, Universidad de Chile, Avenida Beauchef 851, 8370456 Santiago, Chile ³ Departamento de Física, Facultad de Ciencias Naturales, Matemática y Medio Ambiente, Universidad Tecnológica Metropolitana, Santiago, Chile *E-mail: Amitptl195@gmail.com MXenes, a large family of emerging two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides, have demonstrated significant poten - tial in applications such as gas and hu- midity sensing, energy storage, water purification, and electromagnetic inter - ference (EMI) shielding [1-4] . These ma- terials are typically derived from MAX phases, a group of layered ternary compounds with the general formu- la Mn+1AXn (n = 1, 2, or 3), where M is an early transition metal, A is a group 13–14 element, and X is either carbon or nitrogen [6] . MAX phases exhibit a hexa- gonal structure composed of alterna- ting MX and A layers. In this study, we report a bottom-up fabrication me- thod for the deposition and characte- rization of MAX and MXene thin films using magnetron sputtering, aiming at the development of miniaturized, hi- gh-performance gas sensors. Ti₃AlC₂ MAX phase thin films were deposited on Si substrates using DC magnetron sputtering with Ti, Al, C and Ti com- posite targets. Sputtering parameters such as power, working pressure, and gas flow rates were optimised to ensu - re phase purity and dense film grow - th. Post-deposition vacuum annealing improved crystallinity. Subsequent se- lective etching using hydrofluoric acid (HF) removed Al, producing multilaye - red Ti₃C₂T x MXene films. X-ray diffrac - tion (XRD) confirmed the formation of MAX and MXenes phases. Surface characterization using Scanning Elec- tron Microscopy (SEM), Atomic Force Microscopy (AFM), and thickness me- asurements revealed smooth, layered morphologies, while Raman spectros- copy identified surface terminations such as –OH, –F, and –O. Interdigita - ted electrodes were patterned for gas sensing, and resistance changes were monitored upon exposure to NH₃, NO₂, and H₂S. The sensors showed fast res - ponse/recovery times, high sensitivity, and excellent repeatability, attributed to the large surface area and high con- ductivity of the MXenes layers [5,6] . __Agradecimientos Amit Kumar Gangwar gratefully acknowledges the financial support from the ANID– Millennium Science Initiative Program (NCN20223_07). This research was conducted under the MillenniumNucleus of Advanced MXenes for Sustainable Applications (AMXSA), funded by the Agencia Nacional de Investigación y Desarrollo (ANID), Chile. __Referencias [1] Naguib, M., et al, 2014. 26(7): p. 992-1005. [2] Alhabeb, M., et al., 2017. 29(18): p. 7633-7644. [3] Naguib, M., et al., 2023. p. 15-29. [4] Zhao, S., et al., 2018. 12(11): p. 11193-11202. [5] Ren, C.E., et al,2015. 6(20): p. 4026-4031. [6] Torres, C., et al., 2021. 537: p. 147864 Keywords: MXene/MAX phase, Magnetron sputtering, gas sensors, thin films, Ti₃C₂T Resumen