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VOLUME 65 (1997) | ISSUE 11 |
PAGE 834
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Low-temperature resistivity of single crystals YBa2Cu3O6+x in the normal state
Gantmakher V.F., Kozeeva L.P., Lavrov A.N., Pushin D.A., Shovkun D.V., Tsydynzhapov G.E.
![<b>A scan of the superconductor nonsuperconductor transformation in single crystals õ÷ÁÇóÉÚïÂ+È <i>{x </i></b><b>w </b><b>0.37) was done in two alternative ways, namely, by applying the magnetic field and by reducing the hole concentration through the oxygen rearrangement. The in-plane normal-state resistivity p„j obtained in both cases was quite similar; its temperature dependence can be fitted by logarithmic law in the temperature range of almost two decades. However, a different representation of the <r<sub>a</sub>fc ~ 1 <i>/Ò<sub>Á</sub>Ø </i>by a power law typical for a 3D-material near a metal insulator transition is also plausible. The vertical conductivity <i>a<sub>e</sub> ~ l/pc </i>followed the power law and neither <r<sub>c</sub>(T), nor <i>Pc(T) </i>could be fitted by logT. It follows from the <i>p<sub>c</sub> </i>measurements that the transformation at <i>Τ </i>0 is split into two transitions: superconductor normal-metal and normal-metal insulator. In our samples, they are distanced in the oxygen content by Δχ S3 0.025.</b> <b>PACS: 71.30.+h, </b><a href="http://72.30.-i"><b>72.30.-i</b></a><b>, 74.72.Bk</b>](/ps/1007/article_15299_800_head.png)
A scan of the superconductor nonsuperconductor transformation in single crystals õ÷ÁÇóÉÚïÂ+È {x w 0.37) was done in two alternative ways, namely, by applying the magnetic field and by reducing the hole concentration through the oxygen rearrangement. The in-plane normal-state resistivity p„j obtained in both cases was quite similar; its temperature dependence can be fitted by logarithmic law in the temperature range of almost two decades. However, a different representation of the <rafc ~ 1 /ÒÁØ by a power law typical for a 3D-material near a metal insulator transition is also plausible. The vertical conductivity ae ~ l/pc followed the power law and neither <rc(T), nor Pc(T) could be fitted by logT. It follows from the pc measurements that the transformation at Τ 0 is split into two transitions: superconductor normal-metal and normal-metal insulator. In our samples, they are distanced in the oxygen content by Δχ S3 0.025. PACS: 71.30.+h, 72.30.-i, 74.72.Bk
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