Al掺杂对YBaCo4O7氧吸附和电输运性能的影响

摘要

用固态反应法制备了 YBaCo4-x Alx O7(x=0.0,0.1,0.2)样品,研究了从室温~900℃范围内 Al掺杂对氧吸附/脱附和样品电输运性能的影响。Al 掺杂降低了样品在低温区(200~400℃)的氧吸附量,提高了样品在高温区(700~900℃)的相稳定性。此外, Al掺杂减小了样品的空穴浓度和迁移率,提高了样品的电阻率、塞贝克系数和电导活化能。氧吸附/脱附行为和 YBaCo4-x Alx O7样品的电输运性能密切相关。氧吸附增加了空穴浓度,使电阻率和塞贝克系数同时减小。%YBaCo4-xAlxO7(x=0.0,0.1,0.2)samples were prepared by solid state reaction method and the effect of Al doping and oxygen adsorption/desorption on the electronic transport properties was investigated from room temperature to 900 ℃.Al doping decreases the oxygen adsorption capacity in the low temperature region (200-400 ℃)and increases the phase stability in the high temperature region (700-900 ℃).With the in-creasing Al content,the hole concentration and mobility decrease,while the electrical resistivity,Seebeck coef-ficient,and conduction activation energy increase.Moreover,our results show that electronic transport proper-ties are closely related to the oxygen adsorption/desorption process.Oxygen adsorption increases the hole con-centration which results in a drop of electrical resistivity and Seebeck coefficient simultaneously.