GALVANOMAGNETIC EFFECTS AND ELECTRONIC SPECIFIC HEAT OF BULK La2-xBaxCu1-yZnyO4+d

Abstract

The samples of bulk La 2-x Ba x Cu 1-y Zn y O 4+d were prepared by conventional solid state reaction method and have been investigated using electrical resistivity, Seebeck coefficient, Hall coefficient and electronic specific heat measurements over the temperature range between 4.2 K and 300 K in magnetic fields up to 5 T. The samples with y = 0 and d = 0 showed superconductivity for x between 0.055 and 0.30. The critical temperature, the Hall and Seebeck coefficients depend strongly on Zn contents. The phonon specific heat and electronic specific heat have been extracted from the total specific heat, where anomalous x, y and T dependence related to the so-called 1/8 anomaly or the "stripe order" is observed. Zn-doping effect or the behavior γ (T) = Cel/T suggest that large range stripe order and the fluctuating "stripe" suppress the singlet formation and pseudo-gap.