Skutterudite compounds are one of the most promising thermoelectric materials that can be used for intermediate power generation applications because of their excellent thermoelectric and mechanical properties. In spite of extensive research efforts during the past two decades, there is still a lack of full understanding of the electronic and thermal transport in these compounds. In the present study, we carry out a combined experimental and theoretical investigation of the electronic and thermal transport properties of alkaline earth-filled (Ca,Sr,Ba)_0.2Co₄Sb₁₂ skutterudites in the temperature range from 300 K to 800 K. The experimental work includes structural properties probed by PXRD and EMPA for phase purity and composition analysis. Theoretical values of the temperature dependent electronic transport parameters were determined using the nearly-free electron approximation, and various phonon thermal conductivity contributions were studied using the Debye isotropic continuum model and the theory of Price for the bipolar contribution. The theoretical and experimental transport parameters were found in good agreement with each other. They confirm that both Ba and Sr filled skutterudites are highly degenerate semiconductors, while the heat transport in the Ca filled compound is dominated by the bipolar contribution at temperatures above 300 K. The Sr filled skutterudite shows the highest Seebeck coefficient, likely due to its lowest donor ionisation energy. From our detailed theoretical investigations, it is seen that the key mechanism to control the phonon thermal conduction is originated from the interaction between mass defects and phonons. The maximum ZT value obtained 0.14 for Sr_0.2Co₄Sb₁₂ compound at 800 K likely indicate that Sr is more effective filler among the alkaline earth metals.

Skutterudite化合物具有出色的热电和机械性能，是可用于中间发电应用的最有前途的热电材料之一。尽管在过去的二十年中进行了广泛的研究，但仍缺乏对这些化合物中电子和热传递的充分了解。在本研究中，我们对碱土填充（Ca，Sr，Ba）_0.2 Co ₄ Sb ₁₂的电子和热输运性质进行了组合的实验和理论研究。硅藻土的温度范围为300 K至800K。实验工作包括通过PXRD和EMPA探测的结构性质，以进行相纯度和组成分析。使用几乎自由的电子近似值确定与温度相关的电子传输参数的理论值，并使用Debye各向同性连续谱模型和双极贡献的Price理论研究各种声子热导率贡献。发现理论和实验传输参数彼此吻合良好。他们证实，Ba和Sr填充的方钴矿都是高度简并的半导体，而Ca填充的化合物中的热传输受温度高于300 K时的双极贡献支配。充满锶的方钴矿显示出最高的塞贝克系数，这可能是由于其最低的施主电离能。从我们详细的理论研究中可以看出，控制声子热传导的关键机制源自质量缺陷与声子之间的相互作用。Sr的最大ZT值达到0.14在800 K下_0.2 Co ₄ Sb ₁₂化合物可能表明Sr是碱土金属中更有效的填料。