Hopping conductivity in CaCu(2)O(3) single crystals.

Area of Science:

• Condensed matter physics
• Materials science
• Solid-state chemistry

Background:

• Spin-ladder compounds exhibit complex electronic properties.
• Understanding charge transport mechanisms is crucial for materials development.

Purpose of the Study:

• Investigate the electrical resistivity (ρ) of CaCu(2)O(3) between 130-450 K.
• Analyze the temperature dependence of resistivity along different crystallographic directions.
• Determine the appropriate model for charge transport in this material.

Main Methods:

• Resistivity measurements were performed on CaCu(2)O(3) samples.
• Data analysis involved comparing experimental results with various conductivity models.
• Specific focus on activated dependence and variable-range hopping (VRH) regimes.

Main Results:

• Resistivity showed an activated dependence along both [Formula: see text] and [Formula: see text] directions.
• ρ(a)(T) was consistently greater than ρ(b)(T).
• Conventional d-dimensional hopping conductivity models failed to explain the data, showing mismatches in energy and length scales.
• The observed VRH conductivity law (lnρ∼T(-3/4)) contradicted existing models.

Conclusions:

• CaCu(2)O(3) exhibits unique charge transport properties not described by conventional models.
• A model treating the material as a 3D array of quasi-1D electron crystals successfully explains the observed VRH conductivity.
• This finding provides new insights into electron localization and transport in spin-ladder systems.