title: Ionic conductivity and mixed-ion effect in mixed alkali metaphosphate glasses.
abstract: In this work, mixed alkali metaphosphate glasses based on K-Na, Rb-Na, Rb-Li, Cs-Na and Cs-Li combinations were studied by differential scanning calorimetry (DSC), complex impedance spectroscopy, and Raman spectroscopy. DSC analyses show that both the glass transition (Tg) and melting temperatures (Tm) exhibit a clear mixed-ion effect. The ionic conductivity shows a strong mixed-ion effect and decreases by more than six orders of magnitude at room temperature for Rb-Na or Cs-Li alkali pairs. This study confirms that the mixed-ion effect may be explained as a natural consequence of random ion mixing because ion transport is favoured between well-matched energy sites and is impeded due to the structural mismatch between neighbouring sites for dissimilar ions.
authors.affiliation: Universidade Federal de Lavras (UFLA), Departamento de Física (DFI), Campus Universitário, Caixa Postal 3037, CEP: 37200-000, Lavras, MG, Brazil. jefferson.tsuchida@dfi.ufla.br jetsuchida@gmail.com.
authors.forename: Jefferson Esquina
authors.identifier: http://orcid.org/0000-0002-7667-2319
authors.initials: JE
authors.lastname: Tsuchida
authors.affiliation: Departamento de Física (DF), Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil.
authors.forename: Fabio Aparecido
authors.initials: FA
authors.lastname: Ferri
authors.affiliation: Departamento de Física (DF), Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil and Center for Research, Technology and Education in Vitreous Materials (CeRTEV), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil.
authors.forename: Paulo Sergio
authors.initials: PS
authors.lastname: Pizani
authors.affiliation: Center for Research, Technology and Education in Vitreous Materials (CeRTEV), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil and Departamento de Engenharia de Materiais (DEMa) Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil.
authors.forename: Ana Candida
authors.identifier: http://orcid.org/0000-0003-1689-796X
authors.initials: AC
authors.lastname: Martins Rodrigues
authors.affiliation: Center for Research, Technology and Education in Vitreous Materials (CeRTEV), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil and Departamento de Engenharia de Materiais (DEMa) Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil.
authors.forename: Swarup
authors.identifier: http://orcid.org/0000-0001-6905-0661
authors.initials: S
authors.lastname: Kundu
authors.affiliation: Center for Research, Technology and Education in Vitreous Materials (CeRTEV), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil and Instituto de Física de São Carlos (IFSC), Universidade de São Paulo (USP), Av. Trabalhador São-Carlense, 400, CEP: 13566-590, São Carlos, SP, Brazil.
authors.forename: José Fabián
authors.initials: JF
authors.lastname: Schneider
authors.affiliation: Center for Research, Technology and Education in Vitreous Materials (CeRTEV), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil and Departamento de Engenharia de Materiais (DEMa) Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luís, Km 235, CEP: 13565-905, São Carlos, SP, Brazil.
authors.forename: Edgar Dutra
authors.initials: ED
authors.lastname: Zanotto