Transport properties of Li intercalated KCa2Nb3O10

Crystal Structure of a Layered Perovskite Niobate KCa2Nb3O10

“…Similar superconductivity was also reported by Takano et al for the same intercalation compound (6,7). The electric band structure of this superconductor is an important subject for understanding of superconductivity of this system (8,9), but the precise structure is required for the calculation.…”

Electronic structure of the superconducting layered perovskite niobate

“…Very recently, triple-layered perovskite KCa 2 Nb 3 O 10 has been found to be superconducting by intercalating Li (T c ϳ5 K). 3,4 Doublelayered perovskite KLaNb 2 O 7 has also been found to be metallic by intercalating Li, though it shows no superconducting signal down to 0.5 K. 4 These compounds are good insulators without intercalation.…”

Nature of the Bottom t2g-Block Bands of Layered Perovskites. Implications for the Transport Properties of Phases Where These Bands Are Partially Filled

“…As mentioned, KLaNb 2 O 7 exhibits metallic behavior under lithium intercalation 10a. The two Nb−O apical distances in the nonintercalated phase are 1.695 and 2.255 Å, and there is no tilting of the octahedra .…”

“…From all of the compounds we have studied, it is quite clear that even for small differences in the Nb−O apical distances and independently of the fact that the octahedra are tilted or not, for electron fillings lower than those corresponding to a ∼d 0.45 formal configuration of the metal, only the 2D bands should be partially filled. Although it is difficult to guess how effective will be the intercalation process in filling the t 2g bands, the data of Fukuoka et al10c for the triple layer compound Li x KCa 2 Nb 3 O 10 may be taken as suggestive that a d 0.4 situation would not be unreasonable. If this is correct, our analysis suggests that for most intercalated double layer phases with transition metals originally in a d 0 configuration, the conductivity should be 2D and thus be stable metals until low temperatures.…”

“…This area has always been quite active, but the reports of superconductivity in the Li-intercalated triple layer phase Li x KCa 2 Nb 3 O 10 10 triggered the attention of many groups toward these layered perovskites. More intriguingly, the double layer Li-intercalated phase Li x KLaNb 2 O 7 was found to be metallic but did not exhibit superconductivity down to 0.5 K 10a.…”