Al掺杂对YBaCo_4O_7氧吸附和电输运性能的影响

Effect of Al doping on the oxygen adsorption and electronic transport properties of YBaCo_4O_7

用固态反应法制备了YBaCo4-xAlxO7（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-xAlxO7 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.