title: Experimental Evidence of the Origin of Nanophase Separation in Low Hole-Doped Colossal Magnetoresistant Manganites.
abstract: While being key to understanding their intriguing physical properties, the origin of nanophase separation in manganites and other strongly correlated materials is still unclear. Here, experimental evidence is offered for the origin of the controverted phase separation mechanism in the representative La1-xCaxMnO3 system. For low hole densities, direct evidence of Mn(4+) holes localization around Ca(2+) ions is experimentally provided by means of aberration-corrected scanning transmission electron microscopy combined with electron energy loss spectroscopy. These localized holes give rise to the segregated nanoclusters, within which double exchange hopping between Mn(3+) and Mn(4+) remains restricted, accounting for the insulating character of perovskites with low hole density. This localization is explained in terms of a simple model in which Mn(4+) holes are bound to substitutional divalent Ca(2+) ions.
authors.affiliation: Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense (UCM), CEI Moncloa , 28040 Madrid, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Cortés-Gil
authors.affiliation: Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense (UCM), CEI Moncloa , 28040 Madrid, Spain.
authors.forename: M Luisa
authors.initials: ML
authors.lastname: Ruiz-González
authors.affiliation: Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense (UCM), CEI Moncloa , 28040 Madrid, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: González-Merchante
authors.affiliation: Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF , P.O. Box 155, 28230 Las Rozas, Madrid, Spain.|Instituto de Ciencia de Materiales, CSIC , Sor Juana Inés de la Cruz s/n, 28049 Madrid, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Alonso
authors.affiliation: Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF , P.O. Box 155, 28230 Las Rozas, Madrid, Spain.|Departamento de Física de los Materiales, Facultad de Físicas, UCM, CEI Moncloa , 28040 Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Hernando
authors.affiliation: Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz , Campus Rio San Pedro, 11510 Puerto Real, Cádiz, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Trasobares
authors.affiliation: Departamento de Química Inorgánica y Bioinorgánica, Facultad de Farmacia, UCM, CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , 28040 Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Vallet-Regí
authors.affiliation: IMDEA Nanoscience, Ciudad Universitaria de Cantoblanco , C/Faraday 9, 28049 Madrid, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Rojo
authors.affiliation: Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense (UCM), CEI Moncloa , 28040 Madrid, Spain.|Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF , P.O. Box 155, 28230 Las Rozas, Madrid, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: González-Calbet
keywords: Nanophase segregation; atomic resolution; magnetoresistance; manganites