Specific features of spin, charge, and orbital ordering in cobaltites
N.V. Kazaka aL.V. Kirenskii Institute of Physics, Siberian Branch of the Russian Academy of Sciences, Academgorodok 50, stroenie 38, Krasnoyarsk, 660036, Russian Federation bMax-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, Dresden, D-01187, Germany cKazan State University, ul. Lenina 18, Kazan, 420008, Russian Federation
Complex cobalt oxides known as cobaltites are reviewed, including LnCoO3-based perovskite-structured rare-earth cobaltites (where Ln is lanthanum or a lanthanide), quasi-two-dimensional and quasi-one-dimensional cobaltites of the types LnCo2O5+δ, La2CoO4, and Ca3Co2O8, and NaxCoO2 · yH2O superconducting compounds. Key experimental and theoretical results are presented, with emphasis on the interplay between charge, spin, and orbital degrees of
freedom. Two problems of specific relevance to cobaltites — the
spin state instability of Co3+ ions in LnCoO3, and the nature of superconductivity in NaxCoO2 · yH2O also given significant attention.
PACS:71.30.+h, 75.30.Cr, 75.50.Pp (all) DOI:10.3367/UFNe.0179.200908b.0837 URL: https://ufn.ru/en/articles/2009/8/b/ Citation: Ivanova N B, Ovchinnikov S G, Korshunov M M, Eremin I M, Kazak N V "Specific features of spin, charge, and orbital ordering in cobaltites" Phys. Usp.52 789–810 (2009)