Influence of SnO2 concentration on electrical response of alpha-Fe2O3 sintered with different thermal history conditions

Author(s)

Destro, Fabricio B. ; Sczancoski, Julio C. ; Soares, Mario R. S. ; Leite, Edson R.

• Document type: Journal article
• Source: CERAMICS INTERNATIONAL; v. 46, n. 17, p. 7-pg., 2020-12-01.

Abstract

Hematite (alpha-Fe2O3) has been investigated as a promising material for the development of renewable energy technologies. However, intrinsic poor electrical conductivity and fast charge-carrier recombination rate of alpha-Fe2O3 are the limiting factors for such applications. A suitable approach to overcome these limitations is the insertion of electron-donor species into the alpha-Fe2O3 structure. This study describes the effects of incorporating SnO2 with different thermal histories on the electrical properties of alpha-Fe2O3. The sintering temperature at 1300 degrees C was responsible for a significant increase in the average grain sizes compared to the samples sintered at 1100 degrees C. Lower resistivity values were observed in samples obtained at 1100 degrees C with 2.0 wt% SnO2. As such, SnO2 was found to be an excellent modifying agent to favor the overall alpha-Fe2O3 electrical conductivity. Solid-state impedance spectroscopy was adopted as a versatile tool to analyze the occurrence of preferential grain boundaries for electrical current flow. (AU)

• FAPESP's process: 17/03135-5 - Grain boundary in electro-ceramic materials: understanding nature and its function in the hematite (Fe2O3)
• Grantee: Edson Roberto Leite
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 12/14004-5 - Investigation of the photoluminescence and photocatalytic properties of pure and Mn, Cu, and Zn-doped BaWO4 and BaMoO4 powders
• Grantee: Júlio César Sczancoski
• Support Opportunities: Scholarships in Brazil - Post-Doctoral