Gd^(3+) 、Co^(3+)共掺杂铁酸铋薄膜多铁性增强及带隙调谐  

Multiferroic Enhancement and Bandgap Tuning of Gd^(3+) and Co^(3+) Co-Doped Bismuth Ferrite Thin Films

作　　者：马国斌 杨松 徐蕾 郭凯鑫 王旭 MA Guobin;YANG Song;XU Lei;GUO Kaixin;WANG Xu(Guizhou Key Laboratory of Electronic Multifunctional Composite Materials,College of Big Data and Information Engineering,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学大数据与信息工程学院,贵州省电子功能复合材料特色重点实验室,贵阳550025

出　　处：《人工晶体学报》2021年第5期851-857,共7页Journal of Synthetic Crystals

基　　金：国家自然科学基金(61404033);贵州大学国家级重点培育项目(201813);贵州省公共大数据重点实验室开放课题(2017BDKFJJ)。

摘　　要：多铁功能材料在现代生产生活中有举足轻重的作用。本文采用溶胶-凝胶法以硝酸铁、硝酸铋、硝酸钆、硝酸钴为原料,乙二醇甲醚为溶剂,柠檬酸作螯合剂制成前驱体溶液,通过旋涂法在Pt/Ti/SiO_(2)/Si及ITO衬底上合成Bi_(0.85)Gd_(0.15)Fe_(1-x)Co_(x)O_(3)(x=0,0.04,0.08,0.12)薄膜,研究了Gd^(3+)、Co^(3+)共掺杂对薄膜铁电性能、磁学性能及光学带隙的影响。XRD结果表明所有薄膜均呈(111)方向的菱形结构,SEM结果表明共掺杂可以细化晶粒。根据铁电性和漏电流测试分析结果可知在Co^(3+)掺杂量为8%时最大剩余极化值达到2P_(r)=15.71μC/cm^(2),所有样品的漏电流传导机制均为欧姆传导机制。根据磁学性能测试分析结果可知,共掺杂可以有效增强薄膜的饱和磁化强度,且在Co^(3+)掺杂量为8%时最大饱和磁化强度达到37.78 emu/cm^(3)。根据吸收光谱及Tauc公式拟合结果可知共掺杂可以有效减小薄膜的光学带隙且随着掺杂量的增加光学带隙逐渐减小,在Co^(3+)掺杂量为12%时光学带隙减小到1.96 eV。Multiferroic functional materials are of significant importance in modern daily life and industry.Here we report a multiferroic functional material Bi_(0.85)Gd_(0.15)Fe_(1-x)Co_(x)O_(3)(x=0,0.04,0.08,0.12)thin film which was synthesized on Pt/Ti/SiO_(2)/Si and ITO substrates by sol-gel process,involving ferroic nitrate,bismuth nitrate,gadolinium nitrate,cobalt nitrate as raw materials,ethylene glycol methyl ether as solvent,and citric acid as chelating agent forming precursor solution.A comprehensive investigation of structure,ferroelectric property,magnetic property and optical band gap of Gd^(3+)and Co^(3+)co-doping BiFeO_(3)was conducted.XRD results reveal that all films showing a rhombohedral structure in the(111)direction,and SEM results exhibit that co-doping could refine the grains.According to the results of ferroelectricity and leakage current test analysis,the maximum residual polarization value reaches 2P_(r)=15.71μC/cm^(2) when the Co^(3+)doping amount is 8%,at which amount also achieves the maximum saturation magnetization 37.78 emu/cm^(3).The leakage current conduction mechanism of all samples is ohmic conduction mechanism.Last but not least,a modulated bandgap effect according to the absorption spectrum and the fitting results of the Tauc formula were observed.In the co-doping film,the optical bandgap gradually decreases with the increase of the doping amount.In particular,when the Co^(3+)doping amount is 12%,the optical bandgap decreases to 1.96 eV.

关 键 词：溶胶凝胶 铁酸铋 铁电性能 铁磁性能 漏电流 光学带隙 

分 类 号：O484.4[理学—固体物理]