| Autor: |
Lascialfari, A., Ghigna, P., Gennaro, S. De |
| Předmět: |
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| Zdroj: |
International Journal of Modern Physics B: Condensed Matter Physics; Statistical Physics; Applied Physics; 4/20/99, Vol. 13 Issue 9/10, p1151, 6p |
| Abstrakt: |
The charge carrier density plays a crucial role in the transition between normal and superconducting state in the copper-oxide superconductors. In Nd[sub 1.85]Ce[sub 0.15]CuO[sub 4+δ] sample, for charge carrier density n = nc ... 0.07 the superconductivity sets in. In order to investigate the magnetic properties around nc, a set of magnetic susceptibility measurements in the temperature range 3-260K for samples with different charge carriers concentrations were realized. Magnetic susceptibility curves of Nd[sub l.85]Ce[sub 0.15]CuO[sub 4+δ revealed novel behavior well above the critical temperature T[sub c]: at fixed T≥45K, the susceptibility λ, reported as a function of the charge carrier density n, shows a peak around n=0.06 and drops to significantly lower values for n greater than 0.07, the value at which the samples become superconducting. The effective magnetic moment µ[sub eff] shows the same behavior. The comparison of the present experimental results with recent transport ones gives evidence of a possible interaction between charge carriers above T[sub c]. The possibility that this effect could be due to a bipolarons-like mechanism of charge carriers interaction is discussed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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