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Ferromagnetic order in aged Co-doped TiO2 anatase nanopowders
A J Silvestre1, L C J Pereira, M R Nunes
1Instituto Superior de Engenharia de Lisboa and ICEMS, R. Conselheiro Emídio Navarro 1, 1959-007 Lisboa, Portugal.
Journal of Nanoscience and Nanotechnology
|September 12, 2012
Summary
Aged cobalt-doped titanium dioxide (Co:TiO2) nanopowders exhibit significant ferromagnetic properties. These aged materials retain high magnetization, remanence, and coercivity, indicating preserved long-range ferromagnetic order.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Dilute magnetic semiconductors (DMS) are promising for spintronic applications.
- Titanium dioxide (TiO2) is a widely studied semiconductor material.
- Incorporating magnetic elements like cobalt (Co) into TiO2 can induce ferromagnetism.
Purpose of the Study:
- To investigate the ferromagnetic properties of aged cobalt-doped titanium dioxide (Co:TiO2) anatase nanopowders.
- To determine if aging affects the magnetic order and properties of Co:TiO2.
- To quantify the magnetization, remanence, and coercivity of aged Co:TiO2 samples.
Main Methods:
- Synthesis of Ti(1-x)CoxO(2-delta) anatase nanopowders with varying cobalt concentrations (0.03 ≤ x ≤ 0.10).
- Aging of the synthesized Co:TiO2 nanopowder samples.
- Measurement of magnetic properties, including magnetization (M), remanence (Mr), and coercivity (Hc), at room temperature.
Main Results:
- Aged Co:TiO2 anatase nanopowders demonstrated retained high values of magnetization, remanence, and coercivity.
- The measured room temperature M, Mr, and Hc values were in the ranges of [0.05, 0.79] µB/Co, [0.044, 0.096] µB/Co, and [366.7, 494.8] Oe, respectively.
- These magnetic values are comparable to those reported for newly prepared thin films or nanoparticles, indicating preserved long-range ferromagnetic order.
Conclusions:
- Aging does not necessarily degrade the ferromagnetic properties of Co:TiO2 anatase nanopowders.
- The study provides evidence for stable, long-range ferromagnetic order in aged Co:TiO2 samples.
- These findings suggest potential for using aged Co:TiO2 materials in applications requiring stable magnetic properties.
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