学院2014年第二次学术沙龙

发布日期:2014-04-10 作者:null    编辑:    来源:拉斯维加斯0567官方网站

学术沙龙2014年第二场主题报告定于4月11日(周五)下午16:30在物理楼5004报告厅举行,报告人为低维所柴国志老师,届时请各位老师参加。

时间:4月11日(周五)16:30

地点:物理楼5004 报告厅

报告题目:Rotatable anisotropy in magnetic thin films

报告人:柴国志

报告摘要:

Rotatable anisotropy in magnetic thin films is a special type of anisotropy that can only be detected by high frequency measurement other than the traditional VSM B~H loops measurement. Up to now, it can be found in three types of magnetic thin films: (1) thin film with rotatable stripe domain structure, (2) antiferromagnetic/ferromagnetic multilayers, (3) thin film with strong exchange coupling interactions. The following types of magnetic thin films with rotatable anisotropy have been studied. In ferrite doped CoFe thin films, the resonance frequency with 4.5 GHz can be achieved in any direction of the film plane. The high resonance frequency is driven by the rotatable magnetic anisotropy propagated from the exchange coupling between rotatable ferrimagnetic spins and the ferromagnetic grains4. Combine with the rotatable stripe domain structure, the resonance frequency of the film possess zero-field ferromagnetic resonance frequency above 5 GHzafter increasing the thickness of thin film larger than 180 nm. By using the Ta buffer layer, the in plane high frequency permeability can further be optimized to 22 and the resonance frequency will reach 6.4GHz for films with the optimization parameters. As the direction in rotatable anisotropyare angular tunable, we combine the rotatable anisotropy and uniaxial anisotropy (arising from the oblique deposition) in the CoFeBSm thin film. The direction of easy axis can be rotated and the value of resonance frequency can been tuned from 3.8 GHz to 6.4 GHz and by applying a saturated magnetic field in film plane. These results may have a great implication for the tunable microwave magnetic devices.

主讲人:柴国志讲师

柴国志,博士,拉斯维加斯0567官方网站,物理科学与技术学院,讲师,硕士生导师。2011 年起担任格鲁吉亚ShotaRustaveli National Science Foundation 外籍评审专家,2012 年起担任国家自然科学基金评审专家。2008 年以来,在Nature 出版集团的Scientific Reports,美国物理学会的Applied Physics Letters 等国际知名刊物上发表SCI 论文27 篇(截止2014 年2 月,总被引频次134 次,其中单篇论文最高被引26 次)。曾获得首届教育部“博士研究生学术新人奖”,入选拉斯维加斯0567官方网站“优秀博士学位论文培育项目”。主持在研1项国家自然科学基金委员会青年基金项目。主持完成中央高校基本科研业务费专项基金优秀研究生项目1项,天津市东丽区政府创业苗圃项目1项。目前主要从事磁性薄膜、多层膜材料的各向异性、高频磁特性及电磁匹配、材料在GHz 频段的微波磁性测试方法等方面的研究。