Abstract

The effects of Sn⁴⁺ substitution at Cr³⁺ sites on the thermoelectric and electronic properties of p-type delafossite CuCrO₂ have been studied. CuCr_1−xSn_xO₂ (x = 0.01, 0.03) samples were prepared via conventional solid-state reaction. The Seebeck coefficient results confirmed that all the samples exhibited p-type conduction. X-ray photoelectron spectroscopy verified the presence of Sn⁴⁺ ions and the appearance of mixed-state Cr³⁺/Cr²⁺ ions. The experimental results revealed that addition of Sn impacted the electrical conductivity due to the mixed Cu¹⁺/Cu²⁺ states while the Seebeck coefficient was affected by the mixed Cr³⁺/Sn⁴⁺ states. The electrical conductivity was governed by the polaron hopping mechanism, and the large Seebeck coefficient was controlled by the spin and orbital degeneracy of the mixed Cr³⁺/Sn⁴⁺ ions. The electrical conductivity activation energy values were 0.410 eV and 0.407 eV while the thermal activation energy values were 0.208 eV and 0.160 eV, for x = 0.01 and 0.03, respectively. The results confirm that Sn⁴⁺ substitution at Cr³⁺ sites impacted the Seebeck coefficient and electronic behavior of delafossite CuCrO₂ oxide even for low dopant levels of x = 0.01 and 0.03, resulting in p-type conduction and optically conducting materials.

中文翻译：

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Sn 4+在Cr 3+处的取代对p型Delafossite CuCrO 2的热电和电子性质的影响

抽象的

研究了Cr ³⁺位点上Sn ^4+的取代对p型铜铁矿CuCrO ₂的热电和电子性质的影响。 通过常规的固态反应制备CuCr _{1- x} Sn _x O ₂（x = 0.01，0.03）样品。塞贝克系数结果证实所有样品均表现出p型导电性。X射线光电子能谱验证了Sn ⁴⁺离子的存在以及混合态Cr ³⁺ / Cr ^{2+的出现。}离子。实验结果表明，Sn的添加会影响Cu ¹⁺ / Cu ²⁺混合态的导电性，而Seebeck系数会受到Cr ³⁺ / Sn ⁴⁺混合态的影响。电导率由极化子跳跃机制控制，大的塞贝克系数由混合的Cr ³⁺ / Sn ⁴⁺离子的自旋和轨道简并性控制。对于x  ＝ 0.01和0.03，电导率活化能值为0.410eV和0.407eV，而热活化能值为0.208eV和0.160eV 。结果证实Cr处的Sn ⁴⁺取代^3+的位点甚至在x  = 0.01和0.03的低掺杂水平下也会影响铜铁矿CuCrO ₂氧化物的塞贝克系数和电子行为，从而导致p型导电和光导材料。