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Creating thin magnetic layers at the surface of Sb2Te3topological insulators using a low-energy chromium ion beam

Journal Article


Abstract


  • The surfaces of Sb2Te3 topological insulator crystals were implanted using a 40 keV chromium ion beam. To facilitate uniform doping, the Sb2Te3 was passivated with a thin TiO2 film before the implantation step. The resulting chemical structure was studied using atomic-resolution transmission electron microscopy. A fluence of 7 × 1015 ions/cm2 at 40 keV lead to amorphization of the Sb2Te3 surface, with chromium predominantly incorporated in the amorphous layer. Heating to 200 °C caused the amorphous region to recrystallize and led to the formation of a thin chromium-rich interfacial layer. Near-edge x-ray absorption spectroscopy indicates a uniform valence state of Cr3+ throughout, with no evidence of metallic clustering. High-temperature superparamagnetic behavior was detected up to 300 K, with an increased magnetic moment below 50 K.

Publication Date


  • 2020

Citation


  • Cortie, D., Zhao, W., Yue, Z., Li, Z., Bake, A., Marenych, O., . . . Wang, X. (2020). Creating thin magnetic layers at the surface of Sb2Te3topological insulators using a low-energy chromium ion beam. Applied Physics Letters, 116(19). doi:10.1063/5.0006447

Scopus Eid


  • 2-s2.0-85106963490

Volume


  • 116

Issue


  • 19

Abstract


  • The surfaces of Sb2Te3 topological insulator crystals were implanted using a 40 keV chromium ion beam. To facilitate uniform doping, the Sb2Te3 was passivated with a thin TiO2 film before the implantation step. The resulting chemical structure was studied using atomic-resolution transmission electron microscopy. A fluence of 7 × 1015 ions/cm2 at 40 keV lead to amorphization of the Sb2Te3 surface, with chromium predominantly incorporated in the amorphous layer. Heating to 200 °C caused the amorphous region to recrystallize and led to the formation of a thin chromium-rich interfacial layer. Near-edge x-ray absorption spectroscopy indicates a uniform valence state of Cr3+ throughout, with no evidence of metallic clustering. High-temperature superparamagnetic behavior was detected up to 300 K, with an increased magnetic moment below 50 K.

Publication Date


  • 2020

Citation


  • Cortie, D., Zhao, W., Yue, Z., Li, Z., Bake, A., Marenych, O., . . . Wang, X. (2020). Creating thin magnetic layers at the surface of Sb2Te3topological insulators using a low-energy chromium ion beam. Applied Physics Letters, 116(19). doi:10.1063/5.0006447

Scopus Eid


  • 2-s2.0-85106963490

Volume


  • 116

Issue


  • 19