@article{oai:ynu.repo.nii.ac.jp:00003926, author = {Iguchi, E. and Tokuda, Y. and Nakatsugawa, Hiroshi and Munakata, F.}, issue = {4}, journal = {Journal of Applied Physics}, month = {}, note = {application/pdf, In order to identify the carrier responsible for the electrical transport at room temperature in $LiMn_{2}O_{4}$ from the viewpoint of practical applications as a cathode material, the bulk conductivity measurements by complex-plane impedance analyses have been carried out on $LiMn_{2}O_{4}$ ,$Li_{0.95}Mn_{2}O_{4}$, and $LiMn_{1.95}B_{0.05}O_{4} (B=Al^{3} or Ga^{3+}$ together with the measurements of four-probe dc conductivities and dielectric relaxation processes, because these are two candidates for the carrier, a Li ion or a nonadiabatic small polaron of an $e_{g}$ electron on $Mn^{3+}$. The comparison of the ionic conductivity estimated numerically from the parameters obtained experimentally for the Li-diffusion in $LiMn_{2}O_{4}$ with the bulk conductivity indicates that the Li-diffusion seems difficult to play the primary role in the electrical conduction. Instead, a hopping-process of nonadiabatic small polarons of $e_{g}$ electrons is likely to dominate predominantly the electrical transport properties. The dielectric relaxation process, and the activation energies and the pre-exponential factors of the bulk conductivities in $Li_{0.95}Mn_{2}O_{4}$ and $LiMn_{1.95}B_{0.05}O_{4}$ are explained self-consistently in terms of the polaronic conduction.}, pages = {2149--2154}, title = {Electrical transport properties in $LiMn_{2}O_{4}$, $Li_{0..95}Mn_{2}O_{4}$, and $LiMn_{1.95}B_{0.05}O_{4}$ (B=Al or Ga) around room temperature}, volume = {91}, year = {2002} }