| Autor: |
H.S. Refai, M.F. Mostafa, S.S. Ata-Allah, A.A.A. Youssef |
| Rok vydání: |
2008 |
| Předmět: |
|
| Zdroj: |
Journal of Magnetism and Magnetic Materials. 320:344-353 |
| ISSN: |
0304-8853 |
| Popis: |
The (Al and In) doped La – Ca manganites La 0.7 Ca 0.3 Mn 0.96 (In x Al (1− x ) ) 0.04 O 3 with (0.0⩽ x ⩽1.0) were prepared. Structure investigation with X-ray diffraction demonstrates that the doped samples are single perovskite phase with orthorhombic unit cell. Lattice parameters and cell volume were found to increase with increasing In content. The effect of In doping on the IR spectra was discussed. Resistivity measurements carried out in the range 50–300 K for the present series reveal semiconducting behavior at high temperature. As temperature decreased, semiconductor-to-metal (SM) transition occurred at T ρ . This transition shows a strong In content dependence. AC magnetic susceptibility as function of frequency and temperature in the range of 80–300 K for the present doped manganites is reported. Ferromagnetic-to-paramagnetic transition at T c in the range 80–300 K is observed. The effect of applying small DC magnetic field along with the small AC field is found to affect the AC losses. The determined transition temperature is found to decrease as In content increases. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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