Transport and Defect Mechanisms in Cuprous Delafossites. 2. CuScO2 and CuYO2
Transport and Defect Mechanisms in Cuprous Delafossites. 2. CuScO2 and CuYO2
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DOI：
10.1021/cm048982k
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发表时间：
2004-12
影响因子：
8.6
通讯作者：
B. Ingram;B. Harder;N. Hrabe;T. Mason;K. Poeppelmeier
中科院分区：
文献类型：
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作者：
B. Ingram;B. Harder;N. Hrabe;T. Mason;K. Poeppelmeier
铜铁矿结构 (ABO2) 在 B 位上容纳了多种过渡阳离子和稀土阳离子，并结合了一小部分 A 位阳离子。本文报道了铜基铜铁矿材料中 B 位阳离子对缺陷化学和输运的影响，以 CuScO2 和 CuYO2 为例。大 B 位阳离子铜铁矿表现出小极化子传导，这是一种扩散限制传导机制，其活化能大约是 CuAlO2 的两倍（分别为 0.22 eV 和 0.14 eV）。发现这些材料的迁移率<1 cm2 V-1 s-1，进一步证明了小极化子传导。大多数缺陷种类高度依赖于 B 位阳离子，例如 CuScO2 和 CuYO2 主要由外在缺陷（受主掺杂）和自由氧间隙原子组成，而非化学计量的 CuAlO2 占主导地位。对于块状 CuScO2 样品，掺杂剂溶解度为 1%，而在 CuYO2 中则更低。
The delafossite structure (ABO2) accommodates a wide range of transition and rare-earth cations on the B-site in combination with a short list of A-site cations. This paper reports the effects on defect chemistry and transport as a function of the B-site cation in copper-based delafossite materials, with CuScO2 and CuYO2 as examples. Large B-site cation delafossites exhibit small polaron conduction, a diffusion-limited conduction mechanism, with an activation energy approximately twice that of CuAlO2 (0.22 eV vs 0.14 eV, respectively). The mobility for these materials is found to be <1 cm2 V-1 s-1, further evidence of small polaron conduction. The majority defect species is highly dependent on the B-site cation, such that CuScO2 and CuYO2 are dominated by extrinsic defects (acceptor doping) and free oxygen interstitials, whereas off-stoichiometry dominates CuAlO2. Dopant solubility is shown to be 1% for bulk CuScO2 samples and lower in CuYO2.