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 66 0 |
| Căutarea după subiecte similare conform CZU |
| 537.622.5 (1) |
| Электричество. Магнетизм. Электромагнетизм (409) |
 SM ISO690:2012LAIHO, Reino, LISUNOV, Konstantin, LÄHDERANTA, Erkki, SALMINEN, J., ZAKHVALINSKII, Vasilii. Low-field magnetic properties as indication of disorder, frustration and cluster formation effects in La1-xCaxMn1-yFeyO3. In: Journal of Magnetism and Magnetic Materials, 2002, vol. 250, pp. 267-274. ISSN 0304-8853. DOI: https://doi.org/10.1016/S0304-8853(02)00407-9 |
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  Journal of Magnetism and Magnetic Materials |
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| Volumul 250 / 2002 / ISSN 0304-8853 | |||||||
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| DOI:https://doi.org/10.1016/S0304-8853(02)00407-9 | |||||||
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| Pag. 267-274 | |||||||
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Low-field (B=2-80G) DC magnetic susceptibility, χ, is investigated in ceramic La1-xCaxMn1-yFeyO3 (LCMFO) samples with x=0.3. When y is increased from 0 to 0.1 the ferromagnetic (FM) Curie temperature, TC, decreases from 259 to 107K, indicating growth of disorder by iron doping. A transformation of LCMFO from a weakly frustrated FM phase between y≈0-0.05 to a strongly frustrated mixed, FM and glassy, phase between y≈0.07-0.10 is revealed by measurements of magnetic irreversibility and long-time (up to t=105s) relaxation of thermoremanent magnetization. Critical behavior of χ(T) obeying the scaling law χ-1(T)-χ-1(TC)(T/TC-1)γ≡τγ is observed below τcr∼0.05-0.2 with γ=γ1≈1.4 corresponding to a three-dimensional (3D) Heisenberg spin system. Above τcr, χ(T) can be fitted with the same scaling law as for τ<τcr, but with another value of γ=γ2≈1.7, which characterizes a 3D percolation system. The change of γ upon lowering the temperature can be explained by the formation of percolation clusters from an assembly of hole-rich nanoscale particles of the second FM phase embedded into the host LCMFO matrix at T well above TC. The magnetic moments, radii, and concentration of these particles are determined. |
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| Cuvinte-cheie Critical exponents, magnetic clusters, Magnetic phase boundaries |
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DataCite XML Export
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