Temperature Dependence of the Electrical Properties of Na<sub>2</sub>Ti<sub>3</sub>O<sub>7</sub>/Na<sub>2</sub>Ti<sub>6</sub>O<sub>13</sub>/POMA Composites
Salomão Dos Santos Costa,
Juliana Pereira da Silva,
Matheus Moraes Biondo,
Edgar Aparecido Sanches,
Marcos Marques Da Silva Paula,
Francisco Xavier Nobre,
José Anglada Rivera,
Yohandys Alexis Zulueta,
Milton S. Torikachvili,
David Vieira Sampaio,
Marcos Vinicius Dias Vermelho,
Ştefan Ţălu,
Lianet Aguilera Dominguez,
Yurimiler Leyet
Affiliations
Salomão Dos Santos Costa
Department of Physics, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Juliana Pereira da Silva
Department of Materials Engineering, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Matheus Moraes Biondo
Department of Physics, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Edgar Aparecido Sanches
Department of Physics, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Marcos Marques Da Silva Paula
Department of Physics, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Francisco Xavier Nobre
Federal Institute of Education, Science and Technology of Amazonas, Manaus 69020-120, AM, Brazil
José Anglada Rivera
Federal Institute of Education, Science and Technology of Amazonas, Manaus 69020-120, AM, Brazil
Yohandys Alexis Zulueta
Department of Physics, Universidad de Oriente, Santiago de Cuba 90500, Cuba
Milton S. Torikachvili
Department of Physics, San Diego State University, San Diego, CA 92182-1233, USA
David Vieira Sampaio
Institute of Physics, Federal University of Alagoas, Maceió 57072-900, AL, Brazil
Marcos Vinicius Dias Vermelho
Institute of Physics, Federal University of Alagoas, Maceió 57072-900, AL, Brazil
Ştefan Ţălu
The Directorate of Research, Development and Innovation Management (DMCDI), Technical University of Cluj-Napoca, 400020 Cluj-Napoca, Romania
Lianet Aguilera Dominguez
Technological Development Institute (INDT), Manaus 69075-351, AM, Brazil
Yurimiler Leyet
Department of Physics, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
The temperature dependence of the electrical properties of composites formed by biphasic sodium titanate and poly(o-methoxyaniline) (Na2Ti3O7/Na2Ti6O13/POMA) with different concentrations of POMA (0%, 1%, 10%, 15%, 35% and 50%) in the ceramic matrix was determined from measurements of complex impedance. The structural details were studied by means of X-ray diffraction, confirming the formation of the Na2Ti3O7/Na2Ti6O13/POMA composites. The displacement of the (200) reflection from 2θ = 10.45° to 11.15° in the composites with 10 and 15% of POMA suggested the partial replacement of H+ for Na+ in the Na2Ti3O7 structure. The thermal properties were investigated by Thermogravimetry and Differential Thermal Analysis. The Thermogravimetry curves of the composites with POMA content of 1, 10 and 15% presented profiles similar to that of pure sodium titanate sample. The composites with 35 and 50% of POMA showed a process at temperatures around 60–70 °C, which was associated with water absorbed by the polymer. The analysis of the complex impedance spectroscopy measurements revealed that the electrical resistivity of the composites in the range from 0 to 35% increased by two orders of magnitude, with different values for each concentration. This positive temperature coefficient of resistivity was less noticeable in the composite with highest POMA mass content (50%). The rapid increase in resistivity caused an increase in the relaxation time calculated from the time domain. The electrical response of the 50% of POMA compound changes in relation to what was observed in the other compounds, which suggests that there is a saturation limit in the increase in resistivity with POMA content.
