León Yebra, CarlosRivera Calzada, Alberto CarlosVárez, A.Sanz, J.Santamaría Sánchez-Barriga, Jacobo2023-06-202023-06-202001-02-120031-900710.1103/PhysRevLett.86.1279https://hdl.handle.net/20.500.14352/59639© 2001 The American Physical Society. The authors thank H. Jain for providing experimental data of the lithium silicate glass. Financial support from CICYT Grant No. MAT98-1053-C04 is also acknowledged. K. L. N. is supported by ONR.We have analyzed the constant loss contribution to the ac conductivity in the frequency range 10 Hz–1 MHz and temperatures down to 8 K, for two Li ionic conductors, one crystalline (Li_(0.18)La_(0.61)TiO_(3)) and the other glassy (61SiO_(2) . 35Li_(2)O . 3Al_(2)O_(3) . P_(2)O_85)). As temperature is increased a crossover is observed from a nearly constant loss to a fractional power law frequency dependence of the ac conductivity. At any fixed frequency ω, this crossover occurs at a temperature T such that ω = v_(0) exp(-E_(m)/k_(B)T), where v_(0) is the attempt frequency and E_(m) is identified with the barrier for Li^(+) ions to leave their wells.engjournal articlehttp://dx.doi.org/10.1103/PhysRevLett.86.1279http://journals.aps.org/open access537Non-Arrhenius conductivityAC conductivityNonlinear latticesSlow relaxationOxide glassesTemperatureDynamicsSpectraMeltsSpectroscopy.ElectricidadElectrónica (Física)2202.03 Electricidad