C-axis longitudinal magnetoresistance of the electron-doped superconductorPr1.85Ce0.15CuO4

Abstract

We report $c$-axis resistivity and longitudinal magnetoresistance measurements of superconducting ${\mathrm{Pr}}_{1.85}{\mathrm{Ce}}_{0.15}\mathrm{Cu}{\mathrm{O}}_{4}$ single crystals. In the temperature range $13\ensuremath{\leqslant}T\ensuremath{\leqslant}32\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, a negative magnetoresistance is observed at fields just above ${H}_{C2}$. Our studies suggest that this negative magnetoresistance is caused by superconducting fluctuations. At lower temperatures $(T\ensuremath{\leqslant}13\phantom{\rule{0.3em}{0ex}}\mathrm{K})$, a different magnetoresistance behavior and a resistivity upturn are observed, whose origin is still unknown.