Gd掺杂BiFeO3薄膜的溶胶-凝胶法制备和电性能研究

利用溶胶-凝胶工艺在ITO/玻璃衬底上制备了Bi1-xGdxFeO3(x=0.00、0.05、0.10和0.15)薄膜.研究了Gd掺杂对薄膜的结构、形貌、漏电流性能和介电性能的影响.结果显示,未掺Gd和Gd掺杂为5％的样品为菱方结构,当Gd掺杂量达到10％和15％时,样品变为四方结构.掺10％Gd的薄膜样品表面光滑、平整,晶粒大小均匀.Gd的掺入大大降低了BiFeO3(BFO)薄膜的漏电流,其中掺Gd量为10％和15％的薄膜的漏电流几乎为零.在整个测试频率范围内,掺10％Gd的样品的介电常数较大且能保持恒定,同时其介电损耗最小.

Preparation and Electrical Properties of Gd-doping BiFeO3 Thin Films Fabricated by Sol-Gel Method

Bi1-xGdxFeO3 (x=0.00,0.05,0.10,0.15) thin film were prepared on the ITO/glass substrates by sol-gel process.The effects of Gd-doping on the structure,morphology,leakage current and dielectric properties of BiFeO3 thin film were studied.The results show that the structures of the samples with undoping and 5％ Gd-doping are rhombohedral,when Gd doping amount reaches 10％ and 15％,the samples become tetragonal structure.The surface of the thin film with 10％ Gd doping is smooth and uniform grain size.The leakage current of BiFeO3 (BFO) thin films were greatly reduced because of Gd doping.The leakage current of the thin films doped with 10％ and 15％ Gd are almost zero.The dielectric constant of Gd-doped 10％sample is larger and can be kept constant,while its dielectric loss is minimum within the whole test frequency range.