Possible manifestation of spin fluctuations in the temperature behavior of resistivity in Sm_{1.85}Ce_{0.15}CuO_4 thin films

• Published in: arXiv.org
• Main Authors: Sergeenkov, S, Lanfredi, A J C, Araujo-Moreira, F M
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 11.05.2007
• Subjects: Electrical resistivity; Electrons; Phonons; Physics - Superconductivity; Temperature dependence; Thin films; Variation
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0705.1638

A pronounced step-like (kink) behavior in the temperature dependence of resistivity \(\rho (T)\) is observed in the optimally-doped \(Sm_{1.85}Ce_{0.15}CuO_4\) thin films around \(T_{sf}=87K\) and attributed to manifestation of strong spin fluctuations induced by \(Sm^{3+}\) moments with the energy \(\hbar \omega_{sf}=k_BT_{sf}\simeq 7meV\). In addition to fluctuation induced contribution \(\rho_{sf}(T)\) due to thermal broadening effects (of the width \(\omega_{sf}\)), the experimental data are found to be well fitted accounting for residual (zero-temperature) \(\rho_{res}\), electron-phonon \(\rho _{e-ph}(T)=AT\) and electron-electron \(\rho_{e-e}(T)=BT^2\) contributions. The best fits produced \(\omega_p=2.1meV\), \(\tau_0^{-1}=9.5\times 10^{-14}s^{-1}\), \(\lambda =1.2\), and \(E_F=0.2eV\) for estimates of the plasmon frequency, the impurity scattering rate, electron-phonon coupling constant, and the Fermi energy, respectively.