New route for hollow materials

Author(s)

Rivaldo-Gomez, C. M. ; Ferreira, F. F. ; Landi, G. T. ; Souza, J. A.

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 6, AUG 24 2016.
• Web of Science Citations: 4

Abstract

Hollow micro/nano structures form an important family of functional materials. We have used the thermal oxidation process combined with the passage of electric current during a structural phase transition to disclose a colossal mass diffusion transfer of Ti ions. This combination points to a new route for fabrication of hollow materials. A structural phase transition at high temperature prepares the stage by giving mobility to Ti ions and releasing vacancies to the system. The electric current then drives an inward delocalization of vacancies, condensing into voids, and finally turning into a big hollow. This strong physical phenomenon leading to a colossal mass transfer through ionic diffusion is suggested to be driven by a combination of phase transition and electrical current followed by chemical reaction. We show this phenomenon for Ti leading to TiO2 microtube formation, but we believe that it can be used to other metals undergoing structural phase transition at high temperatures. (AU)

• FAPESP's process: 16/09769-3 - Synthesis and Physical Properties Characterization of microtubes
• Grantee: José Antonio Souza
• Support type: Regular Research Grants
• FAPESP's process: 13/16172-5 - Synthesis and characterization of physical properties of nanosized materials
• Grantee: José Antonio Souza
• Support type: Regular Research Grants
• FAPESP's process: 15/10900-4 - Synthesis and Physical Properties Characterization of Hierarchically Micro/nanostructured Materials
• Grantee: Cynthia Marina Rivaldo Gómez
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/01218-2 - Stochastic processes applied to out-of-equilibrium systems
• Grantee: Gabriel Teixeira Landi
• Support type: Regular Research Grants