Böhmer, RolandRanko, Richert2008-06-112008-06-111999Richert, R.; Böhmer, R.: Heterogeneous and homogeneous diffusivity in an ion conducting glass. In: Physical Review Letters Nr. 21, Jg. 83(1999), S. 4337-4340, doi: 10.1103/PhysRevLett.83.4337.http://hdl.handle.net/2003/2549210.17877/DE290R-7493The nature of ion diffusivity in the vitreous conductor 2Ca(NO3)2̇3KNO3 (CKN) was studied by nonresonant dielectric hole burning. Spectral holes in the electric field relaxation are probed subsequent to a high electric sinusoidal burn field. For sufficiently high pump frequencies we are able to induce spectrally selective modifications in the relaxation of the electric modulus, indicating that ionic diffusivity is a spatially varying quantity in glassy CKN. Homogeneous behavior occurs in the regime of low pump frequencies, in which the resistivity approaches its steady state value. Thus, longer-ranged ionic motions lead to a spatial averaging over the heterogeneity of local ion diffusivities.enThe American Physical Society53010.1103/PhysRevLett.83.4337article (journal)