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SM ISO690:2012 LISUNOV, Konstantin, WIZENT, Nadja, WASKE, Anja, WERNER, Johannes, TRISTAN, Neumann, SEKAR, Chinnathambi, KRABBES, Gernot, BEHR, Gunther U., ARUSHANOV, Ernest, BUCHNER, Bernd B.. Quasi-one-dimensional hopping conductivity of the spin-ladder CaCu2 O3 single crystals: Influence of the cation and oxygen nonstoichiometry. In: Journal of Applied Physics, 2008, vol. 103, pp. 1-6. ISSN 0021-8979. DOI: https://doi.org/10.1063/1.2946451 |
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Journal of Applied Physics | ||||||
Volumul 103 / 2008 / ISSN 0021-8979 /ISSNe 1089-7550 | ||||||
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DOI:https://doi.org/10.1063/1.2946451 | ||||||
Pag. 1-6 | ||||||
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The resistivity ρ (T) of the spin-ladder compound CaCu2 O3 measured along the Cu-O-Cu leg (jb) exhibits a strongly activated character. It increases from ∼ 104 to ∼ 109 m if T decreases from 350 to 100 K. The charge transfer above T∼200 K is governed by a quasi-one-dimensional (1D) nearest-neighbor hopping (NNH) conductivity mechanism characterized by the law ρ (T) ∼exp (Ea /kT). Below 200 K a novel quasi-1D variable-range hopping (VRH) conductivity law ρ (T) ∼exp [(T0 /T) 3/4] is observed, predicted recently by Fogler, Teber, and Shklovskii [Phys. Rev. B 69, 035413 (2004)]. The NNH activation energy Ea and the VRH characteristic temperature T0 exhibit high sensitivity to the cation (Ca, Cu) content, decreasing by 2.3-2.5 times and by 3.0-3.2 times, respectively, when the composition of Ca is changed from 0.854 to 0.786-0.798 and the composition of Cu from 2.039 to 2.159-2.163. The behavior of Ea and T0 can be attributed to a corresponding variation of the concentration of intrinsic defects associated with Cu vacancies. On the other hand, no direct dependence of Ea and T0 to the excess oxygen concentration is observed. |
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Cuvinte-cheie Engineering controlled terms Activation energy, calcium, Charge transfer, chemical activation, copper, Copper alloys, crystallography, ion exchange, ketones, oxygen, Ozone water treatment, Positive ions, Spin dynamics, Structure (composition) Engineering uncontrolled terms American Institute of Physics (AIP), Characteristic temperatures, concentration (composition), excess oxygen, High sensitivity (HS), Hopping conductivity, Intrinsic defects, Nearest Neighbor (NN), Oxygen-non stoichiometry, Quasi one dimensional (Q1D), Variable-range hopping Engineering main heading Single crystals |
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