SmCo及SmCo/TbDyFe薄膜的制备与研究

【作者】 邱轶；

【导师】 赵恂；

【作者基本信息】 国防科学技术大学 ， 材料学， 2002， 硕士

【摘要】 本论文对磁控溅射制备的SmCo、TbDyFe、SmCo／TbDyFe薄膜性质进行了研究，以期提高TbDyFe薄膜的磁致伸缩性能尤其是在低磁场下的磁致伸缩性能。 通过正交试验法得到了实验条件下镀制SmCo薄膜最佳的工艺参数：靶-基距6cm、功率80W、Ar气压强1.1Pa。研究了薄膜成分、厚度以及退火热处理对SmCo薄膜磁性能的影响规律。研究结果表明，由于杂质Fe的掺入降低了SmCo薄膜的磁性能；制备态SmCo薄膜为非晶态结构，矫顽力Hc随着薄膜厚度的增加而减小，剩磁比Mr／Ms随膜厚增加而增加；经过500℃真空退火热处理后，薄膜出现SmCos的结晶物，矫顽力Hc降低，Mr／Ms减小，磁化机制由畴壁钉扎类模型转为形核类模型。 完善了薄膜磁致伸缩系数测量结果的处理程序，研究了磁致伸缩薄膜在外场作用下薄膜弹性模量的变化对磁致伸缩值的影响，使测量得到的数据可靠性提高，数据的处理结果更符合实际。 研究了热处理对TbDyFe薄膜结构及磁性能的影响。结果表明，制备态薄膜为非晶态结构，经过500℃真空退火热处理后，薄膜出现了TbFe₂的结晶物，薄膜的矫顽力和外场的饱和磁场大大降低，饱和磁化强度增强，初始磁化率提高，易磁化轴转向膜面。 对TbDyFe薄膜的磁致伸缩特性进行了研究。制备的TbDyFe薄膜的磁致伸缩值λ在H=100kA／m下达到120×10^-6，在H=330kA／m时λ=240×10^-6。退火热处理和衬底粗糙度的降低有助于薄膜磁致伸缩性能的提高。 对SmCo／TbDyFe复合薄膜磁致伸缩特性的研究表明，SmCo薄膜的复合能提高磁致伸缩薄膜的磁化率和饱和磁化强度从而提高TbDyFe薄膜磁致伸缩性能。制备的超磁致伸缩复合薄膜所达到的磁致伸缩值为：磁场强度H=100kA／m下λ=140×10^-6，H=330kA／m下λ=320×10^-6。更多还原

【Abstract】 The properties of SmCo TbDyFe films and SmCo/TbDyFe bilayer films prepared by D.C.magnetron sputtering were investigated in this paper. The purpose of the research was to find a way to improve the magnetostriction of TbDyFe films,especially in low magnetic field.The optimal technological parameters of SmCo thin films were determined as 60mm distance between the target and the substrate,SOW sputtering power and 1.1 Pa Ar pressure through thorgonal experiments. X-ray diffraction results revealed that the structure of as-deposited SmCo film was amorphous and crystallization happened after the films annealed at 500 in vacuum. The magnetic tests of SmCo thin films showed that its coercivity reduced with the increase of film’s thickness while the ratio of Mr/Ms was opposite. The films’ coercivity and Mr/Ms declined after it annealed at 500 because the machanism of magnetization were changed from domain wall nailing into magnetic nuclear forming.In this paper,the program of measure system for films’ magnetostriction was improved and the influence of TbDyFe thin films’ elastic modulus on measurement was also studied.The effects of annealing on the microstructure and magnetic performance of TbDyFe ihin films was researched. The results showed that the microstructure of as-deposited TbDyFe II 1ms were amorphous and the crystal of TbFe2 were found in films after annealing at 500 . Annealing films in vaccum could improve the saturation magnetization Ms and the susceptibility,decrease the coercivity and the saturaion field,and make the direction of the magnetic moments parallel to the film plane.The investigation of the magnetostriction of TbDyFe thin films resulted to the conclution that the heat treatment and the improvement of substrate smoothness could improve films’ magnetostriction. The better magnetostriction of TbDyFe thin films was 120X 10-6 in 100kA/m and 240 X 10-6 in 330kA/mThe research on the magnetostriction of SmCo/TbDyFe bilayer films indicated that SmCothin films could improve the magnetostricion of TbDyFe thin films effectively through improving its saturation magnetization Ms and susceptibility. The better magnetostriction of SmCo/TbDyFe bilayer films was 140 X 10-6 in 100kA/m and 320 X10-6 in 330kA/m更多还原