2002/10/21 by G. C. Papavassiliou, G. Papavassiliou, M. Belesi +7 · 2 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Rare-earth and actinide compounds #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.91.147205
4 pages, 4 figures
arxiv created 2002/10/21 · openalex publication_date 2003/10/03 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
55Mn and 139La NMR measurements on a high quality single crystal of ferromagnetic (FM) La0.80Ca0.20MnO3 demonstrate the formation of localized Mn3+,4+ states below 70 K, accompanied by a strong cooling-rate dependent increase of certain FM neutron Bragg peaks. 55,139(1/T1) spin-lattice and 139(1/T2) spin-spin relaxation rates are strongly enhanced on approaching this temperature from below, signaling a genuine phase transition at Ttr\ensuremath≃70 K. The disappearance of the FM metallic signal by applying a weak external magnetic field, the different NMR radio-frequency enhancement of the FM metallic and insulating states, and the observed finite size scaling of Ttr with Ca (hole) doping, as observed in powder La_1\ensuremath-xCaxMnO3 samples, are suggestive of freezing into an inhomogeneous FM insulating and orbitally ordered state embodying ``metallic'' hole-rich walls.