Effect of vacuum-annealing on the d0 ferromagnetism of undoped In2O3 films

• Published in: Journal of magnetism and magnetic materials Vol. 324; no. 18; pp. 2932 - 2935
• Main Authors: Sun, Shaohua, Wu, Ping, Xing, Pengfei
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2012; Elsevier
• Subjects: Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; d0 ferromagnetism; Deposition; Deposition by sputtering; Domain effects, magnetization curves, and hysteresis; Exact sciences and technology; Ferromagnetism; Grain boundaries; Indium oxide; Indium oxides; Joints; Magnetic properties and materials; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Oxygen vacancy; Physics; Radiofrequency magnetron sputtering; Saturation (magnetic); Silicon substrates; Studies of specific magnetic materials; Treatment of materials and its effects on microstructure and properties; Vacancies; Vacuum-annealing; Radiofrequency magnetron sputtering; d0 ferromagnetism; Indium oxide; Vacuum-annealing; Oxygen vacancy; Grain boundaries; Annealing; nnealing; d; Magnetic moments; Vacancy cluster; Nonstoichiometry; Interfaces; Cathode sputtering; Vacuum; Ferromagnetism; Scanning transmission electron microscopy; Radiofrequency sputtering; Saturation magnetization; Magnetic properties
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2012.04.050

Vacuum-annealing was carried out on the pure indium oxide films deposited on Si (100) substrates by radiofrequency magnetron sputtering. Oxygen-deficiency states and room temperature d0 ferromagnetism were both detected in the as-grown and vacuum-annealed films. With more oxygen vacancies appeared through vacuum-annealing, the saturation magnetization increased rapidly from 0.5 to 5.5emu/cm3. The connection between the highly oxygen-deficiency states and the strong magnetic moment suggests that oxygen vacancies play a crucial role in mediating the ferromagnetism in In2O3 films. We think that this d0 ferromagnetism mainly stems from V0+ and oxygen vacancy clusters in the interfaces or grain boundaries. ► Effect of vacuum-annealing on the d0 ferromagnetism of pure In2O3 films. ► d0 ferromagnetism both exists in the as-grown and vacuum-annealed In2O3 films. ► Highly oxygen-deficiency state of the annealed In2O3 film was characterized by XPS. ► An enhancement in the moment from 0.5 to 5.5emu/cm3 was achieved upon annealing. ► The d0 ferromagnetism in our pure In2O3 films is related to oxygen vacancies.