| Autor: |
N.V. Baranov, Bogdan Kotur, Herwig Michor, P.E. Markin, A.A Yermakov, U.M Possokhov, B Weingartner, G Hilscher |
| Rok vydání: |
2001 |
| Předmět: |
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| Zdroj: |
Journal of Alloys and Compounds. 329:22-30 |
| ISSN: |
0925-8388 |
| DOI: |
10.1016/s0925-8388(01)01585-7 |
| Popis: |
The variation of lattice parameters, magnetic, transport and thermodynamic properties were investigated in the pseudobinary system (Gd 1− x Y x ) 3 Co. A field-induced phase transition from the antiferromagnetic to the ferromagnetic state is observed below the Neel temperature, which is accompanied by giant magnetoresistance for x γ , for Y 3 Co is found to be significantly lower (15 mJ mol −1 K −2 ) than for the isostructural Gd 3 Co compound (109–170 mJ mol −1 K −2 ). This remarkable difference in the γ values is ascribed to a significant spin fluctuation contribution of the d-electron subsystem which is induced by the Gd-subsystem. With increasing yttrium content the γ value changes non-monotonously yielding a maximal value as high as 350 mJ mol −1 K −2 at x =0.8 where also a peak of the residual resistivity is observed. For lower Y content ( x S m deviates significantly from the theoretical value S max m =3 R (1− x )ln 8 even at temperatures of about two times T N . The discrepancy between S m and S max m in the paramagnetic region as well as the saturation of the electrical resistivity at T > T N in Gd 3 Co is attributed to the presence of short-range correlations between Gd-moments and to spin fluctuations in the d-electron subsystem well above the ordering temperature. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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