High-pressure effect on transport properties of spin-ladder compounds Na1-xCaxV2O5 and Ca0.7Li0.3V2O5

Electrical resistivity of layered vanadium oxides Na1-xCaxV2O5 and Ca0.7Li0 .3V2O5 has been measured under high pressures of up to 10 GPa. These compou nds have V-O networks forming a two-leg spin-ladder layer in some compositi on range. In the spin-ladder compound Na1-xCaxV2O5, electrical resistivity measurements show semiconducting behavior. However. the electrical resistiv ity has been significantly reduced under high pressure, although it remains semiconducting up to 8 GPa. On the other hand, the electrical resistivity of Ca0.7Li0.3V2O5 which also has a two-leg spin-ladder layer is lower than Na1-xCaxV2O5 by several orders of magnitude. The electrical resistivity of Ca0.7Li0.3V2O5 was greatly reduced even at low-temperature range by applyin g pressure. (C) 2001 Elsevier Science B.V. All rights reserved.