Charge dynamics of 57Fe probe atoms in La2Li0.5Cu0.5O4 |
| |
| Institution: | 1. Lomonosov Moscow State University, Moscow, Russia;2. Ural Federal University, Ekaterinburg, Russia;1. College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Longteng Road 333, 201620 Shanghai, PR China;2. Department of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany;1. Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Sangareddy 502 285, Telangana, India;2. Department of Pure and Applied Physics, Guru Ghasidas Vishwavidyalaya, Koni, Bilaspur 495 009, Chhattisgarh, India;1. Universidad de Buenos Aires, Consejo Nacional de lnvestigaciones Científicas y Técnicas, Instituto de Tecnología y Ciencias de la Ingeniería “Ing. Hilario Fernández Long” (INTECIN), Av. Paseo Colón 850, C1063ACV, Ciudad Autónoma de Buenos Aires, Argentina;2. Departamento de Física Aplicada – Instituto Universitario de Ciencia de los Materiales, Universitat de València (ICMUV), 46100, Burjassot, Valencia, Spain;1. Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India;2. Chemistry Department, University of Coimbra, 3004-535 Coimbra, Portugal;3. Nanomaterials Laboratory, Kalasalingam University, Krishnankoil 626 126, Tamil Nadu, India;4. Department of Biochemistry, Srimad Andavan Arts and Science College, Tiruchirappalli 620 005, Tamil Nadu, India;1. Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands;2. CNR-ISMN, Instituto per Io Studio di Materiali Nanostrutturati, Via Gobetti 101, I-40129 Bologna, Italy;3. Dipartimento di Scienze, Università di Roma Tre, I-00146 Rome, Italy;4. Consiglio Nazionale delle Ricerche, CNR-IOM, Laboratorio TASC, Area Science Park, I-34149 Trieste, Italy |
| |
| Abstract: | The objective of this study is to characterize the electronic state and local surrounding of 57Fe Mössbauer probe atoms within iron-doped layered perovskite La2Li0.5Cu0.5O4 containing transition metal in unusual formal oxidation states “+3”. An approach based on the qualitative energy diagrams analysis and the calculations within the cluster configuration interaction method have been developed. It was shown that a large amount of charge is transferred via Cu-O bonds from the O: 2p bands to the Cu: 3d orbitals and the ground state is dominated by the d9L configuration (“Cu2+-O-” state). The dominant d9L ground state for the (CuO6) sublattice induces in the environment of the 57Fe probe cations a charge transfer Fe3+ + O−(L) → Fe4+ + O2−, which transforms “Fe3+” into “Fe4+” state. The experimental spectra in the entire temperature range 77–300 K were described with the use of the stochastic two-level model based on the assumption of dynamic equilibrium between two Fe3+↔Fe4+ valence states related to the iron atom in the Fe(1)O4]4- center. The relaxation frequencies and activation energies of the corresponding charge fluctuations were estimated based on Mössbauer data. The results are discussed assuming a temperature-induced change in the electronic state of the CuO4]5- clusters in the layered perovskite. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
