摘要
Adding both La3+and Co3+was used to tune the microstructure and electrical properties of Bi Fe O3(BFO) thin films, and Bi1-xLaxFe0.90Co0.10O3 thin films were grown on the Sr Ru O3-buffered Pt-coated silicon substrates by a radio frequency sputtering. A polycrystalline structure with(110) orientation was shown in thin films, and their resistivity dramatically increases as the La3+content increases. Their dielectric constant increases,and dielectric loss decreases with increasing La3+content.In addition, their ferroelectric and fatigue properties were enhanced with rising La3+content. The thin films with x = 0.03 have optimum electrical properties(e.g., remanent polarization 2Pr* 175.6 l C/cm2, coercive field2Ec* 699.5 k V/mm, dielectric constant er* 257 and tan d * 0.038), together with a good fatigue behavior. The impendence analysis of the films was conducted to identify the defects type during conductivity, and both hopping electrons and single-charged oxygen vacancies are mainly responsible for the conduction of grain and grain boundaries regardless of La3+content. As a result, the doping with both La3+and Co3+benefits the improvement in the electrical properties of BFO thin films.
Adding both La3＋and Co3＋was used to tune the microstructure and electrical properties of Bi Fe O3（BFO） thin films, and Bi1-xLaxFe0.90Co0.10O3 thin films were grown on the Sr Ru O3-buffered Pt-coated silicon substrates by a radio frequency sputtering. A polycrystalline structure with（110） orientation was shown in thin films, and their resistivity dramatically increases as the La3＋content increases. Their dielectric constant increases,and dielectric loss decreases with increasing La3＋content.In addition, their ferroelectric and fatigue properties were enhanced with rising La3＋content. The thin films with x = 0.03 have optimum electrical properties（e.g., remanent polarization 2Pr＊ 175.6 l C/cm2, coercive field2Ec＊ 699.5 k V/mm, dielectric constant er＊ 257 and tan d ＊ 0.038）, together with a good fatigue behavior. The impendence analysis of the films was conducted to identify the defects type during conductivity, and both hopping electrons and single-charged oxygen vacancies are mainly responsible for the conduction of grain and grain boundaries regardless of La3＋content. As a result, the doping with both La3＋and Co3＋benefits the improvement in the electrical properties of BFO thin films.
基金
supported by the National Natural Science Foundation of China(51472169,51102173 and11002126)
the introduction of talent start funds of Sichuan University(2082204144033)
the College of Materials Science and Engineering of Sichuan University
关键词
电性能
薄膜
掺杂
微结构
抗疲劳性能
Co
LA
介电常数
Multiferroic materials
Bismuth ferrite
Microstructure
Electrical properties
Fatigue
Conduction mechanism
