Instability of magnetism and conductivity in CMR manganites: role of Mn-site doping and thermal cycling |
| |
| Institution: | 1. Laboratoire CRISMAT, ISMRA et Universite de Caen, UMR 6508 associée au CNRS, 6 Boulevard du Maréchal Juin, 14050 Caen Cedex, France;2. Solid State Physics Laboratory, Materials Science Center, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands;1. Department of Physics, Saurashtra University, Rajkot 360005, India;2. Department of Nanoscience & Advanced Materials, Saurashtra University, Rajkot 360005, India;1. Department of Civil Engineering and Architectural Engineering, University of Pavia, Via Ferrata 1, 27100 Pavia, Italy;2. Department of Civil, Environmental, Architectural Engineering, and Mathematics, University of Brescia, Via Branze 43, 25123 Brescia, Italy;1. School of Material Science and Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials,Shaanxi University of Science and Technology, Xi''an, 710021, China;2. School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin, 150001, China;3. Heilongjiang University of Science and Technology, Harbin 150027, China;4. Institute of Electrochemistry, Clausthal University of Technology, Arnold-Sommerfeld-Strasse 6, 38678 Clausthal-Zellerfeld, Germany;5. College of Materials Science and Engineering, Central South University, Changsha, 410083, China;6. College of Materials Science and Engineering, Beijing University of Technology, Chaoyang District, Beijing 100124, China;7. Center for Composite Materials, Harbin Institute of Technology, Harbin, 150001, China;1. Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin, Italy;2. School of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2147, Valparaíso, Chile;3. Center for Sustainable Future Technologies, CSF@PoliTo, Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Turin, Italy;4. Department of Civil and Mechanical Engineering, Università degli Studi di Cassino e del Lazio Meridionale, Via G. Di Biasio 43, 03043 Cassino, FR, Italy;5. INSMT Unit of Torino-Politecnico, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin, Italy;1. Akdeniz University, Physics Department, Science Faculty, TR-07058 Antalya, Turkey;2. Uludag University, Physics Department, Science and Literature Faculty, TR-16059 Bursa, Turkey;3. Balikesir University, Physics Department, Science and Literature Faculty, TR-10145 Balikesir, Turkey |
| |
| Abstract: | The magnetic and transport properties of the manganites with the perovskite structure are mainly characterized by a competition between ferromagnetism and antiferromagnetism, and between a metallic like and an insulating behavior. Charge and orbital ordering, and phase separation play a prominent role in the appearance of such properties, since they can be modified in a spectacular manner by external factors, making the different physical properties metastable. There we describe two effects that deeply modify those properties, the doping of Mn sites and the thermal cycling under a magnetic field.The doping of Mn sites by various magnetic cations—Cr, Co, Ni, Ru, Rh, Ir—destroys charge/orbital-ordering and induces ferromagnetism and metallicity in the antiferromagnetic matrix of the manganites. The magnetic phase diagram of the systems Ln1?xCaxMnO3 is considerably modified by such doping. The metastability of the magnetic states is explained in terms of models based on the electronic structure of the doping elements in connection with a possible valence fluctuation.The thermal cycling is also a spectacular effect, observed in chromium doped manganites. For instance, an increase of resistivity by several orders of magnitude can be observed by thermal cycling under a magnetic field, whereas no effect is obtained in the corresponding undoped material. This behavior is interpreted in terms of strains induced charge localization, at the interface between ferromagnetic/antiferromagnetic domains in the antiferromagnetic matrix. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
