| Autor: |
The-Long Phan, Seong-Cho Yu, Van Khiem, Nguyen, Manh-Huong Phan, Jang Roh Rhee, Nguyen Xuan Phuc |
| Zdroj: |
Journal of Applied Physics; 5/15/2005, Vol. 97 Issue 10, p10A508-1-10A508-3, 3p, 1 Chart, 5 Graphs |
| Abstrakt: |
Spin dynamics and magnetic frustration effects in La0.5Sr0.5Co1-xFexO3 (0⩽x⩽0.6) compounds were systematically studied by means of resistivity, dc magnetization, ac susceptibility, and electron-spin-resonance spectra. The Fe substitution caused a metal-semiconductor transition for x⩽0.3 compositions whereas the only semiconducting state behaved for x>0.3 compositions. With increasing Fe-doping levels, the ferromagnetic-paramagnetic transition temperature, TC, decreased from 250 (x=0) to 166 K (x=0.4). A spin-glass behavior was observed for x>0.4 compositions and is attributed to the frustration of random competing exchange interactions, namely, the ferromagnetic Co3+-Co4+ double-exchange interaction and the antiferromagnetic interactions such as Co-O-Fe and Fe-O-Fe. The internal dynamic properties of the samples were elucidated by the electron-paramagnetic-resonance spectra. An electronic and magnetic phase diagram of La0.5Sr0.5Co1-xFexO3 is drawn up. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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