Role of boundaries on low-field magnetotransport properties of La0.7Sr0.3MnO3-based nanocomposite thin films
| Autor: | Chen-Fong Tsai, Qing Su, Jie Jian, Haiyan Wang, Judith L. MacManus-Driscoll, Quanxi Jia, Wenrui Zhang, Aiping Chen |
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| Rok vydání: | 2013 |
| Předmět: |
010302 applied physics
Phase boundary Materials science Nanocomposite Magnetoresistance Misorientation Condensed matter physics Mechanical Engineering Percolation threshold 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Grain size Mechanics of Materials Phase (matter) 0103 physical sciences General Materials Science Grain boundary 0210 nano-technology |
| Zdroj: | Journal of Materials Research. 28:1707-1714 |
| ISSN: | 2044-5326 0884-2914 |
| DOI: | 10.1557/jmr.2013.89 |
| Popis: | The effects of boundaries such as grain boundaries and phase boundaries on low-field magnetoresistance (LFMR) have been investigated in single-phase lanthanum strontium manganates, in this case La0.7Sr0.3MnO3 (LSMO) and LSMO: zinc oxide (ZnO) nanocomposite thin films. In the pure LSMO films with similar grain size, it is found that the LFMR increases as the grain misorientation factor (β) increases. The LFMR in the nanocomposite films is greatly enhanced, as compared with single-phase films, due to the reduced grain size, and increased phase boundary (PB) and β effects. The composition study shows that the LFMR can be dramatically enhanced when the secondary phase content approaches the percolation threshold. The increased β and secondary phase concentration reduce the cross-section of electron conduction paths and favor the formation of the quasi-one-dimensional transport channels. Our results demonstrate that the reduction of cross-section of the electron conduction paths by tuning the grain orientation and secondary phase composition is necessary for enhancing LFMR effect. |
| Databáze: | OpenAIRE |
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