{"paper":{"title":"Transport Properties in (Na,Ca)Co_2O_4 Ceramics","license":"","headline":"","cross_cats":[],"primary_cat":"cond-mat.str-el","authors_text":"I. Terasaki, T. Itoh, T. Kawata, T. Kitajima","submitted_at":"1999-08-03T08:46:16Z","abstract_excerpt":"The resistivity and thermopower of polycrystalline (Na,Ca)Co_2O_4 were measured and analyzed. Both the quantities increase with x, suggesting that the carrier density is decreased by the substitutions of Ca^{2+} for Na^{+}. Considering that the temperature dependence of the resistivity show a characteristic change with x, the conduction mechanism is unlikely to come from a simple electron-phonon scattering. As a reference for NaCo_2O_4, single crystals of a two-dimensional Co oxide (Bi,Pb)_2M_3Co_2O_9 (M=Sr and Ba) were studied. The Pb substitution decreases the resistivity, leaving the thermo"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"cond-mat/9908039","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/cond-mat/9908039/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}