Normal-state anomalies in the transport and magnetic properties in the (La1-xPrx)(1.85)Sr0.15CuO4 system and their correlation with T-c suppression: A signature of the effects of orthorhombic distortions
Je. Musa et al., Normal-state anomalies in the transport and magnetic properties in the (La1-xPrx)(1.85)Sr0.15CuO4 system and their correlation with T-c suppression: A signature of the effects of orthorhombic distortions, PHYS REV B, 59(9), 1999, pp. 6557-6562
The correlation between the normal-state anomalies observed in the magnetic
and transport properties of the (La1-xPrx)(1.85)SR0.15CUO4 system with 0 l
ess than or equal to x less than or equal to 0.5 was studied. The x-ray-dif
fraction patterns revealed a linear increase of the (a-b) orthorhombic para
meter with the Pr content. The resistivity curves showed an increasing devi
ation from linearity below similar to 100 K. This anomaly was properly acco
unted by a logarithmic term, whose coefficient C linearly increases with x.
Superconducting quantum interference device measurements of the normal-sta
te magnetic susceptibility evidenced a deviation from the Pr3+ Curie-Weiss
behavior in the same temperature range for which the resistivity anomaly oc
curs. This behavior is explained in terms of an induced magnetic moment at
the CuO2, layers under strain. A Dzialoshinsky-Moriya interaction, associat
ed to the orthorhombic distortions, is proposed to be the source of a weak
canted ferromagnetic component, which develops in conjunction with an enhan
cement of the antiferromagnetic correlations. A comprehensive picture of th
e conduction mechanism for the whole system is presented in terms of a Kond
o-like scattering of the mobile holes by the spin fluctuations at the condu
ction planes. T-c suppression was found to correlate with C, suggesting tha
t the excitation which interacts with the carriers in the normal state is r
elevant for superconductivity. [S0163-1829(99)11505-4].