欢迎来到柴国志教授“布里渊光散射&微波磁学”课题组

祝贺郝振慧同学转博，欢迎2023级硕士生安康、谢樱楠、曹雨萌！2023.09.01

本课题组主要从事布里渊光散射、磁振子-光子相互作用；磁性薄膜、多层膜材料的各向异性、高频磁特性和材料在GHz 频段的微波磁性测试方法等方面的研究。主要的研究方向如下：

布里渊光散射、磁振子晶体
光子-磁振子相互作用
自旋动力学
磁功能器件
微波测试与微波成像

本研究组同国内外众多知名研究组有长期紧密的学术合作和人才交流，欢迎读研究生或做本科生毕业设计、创新实验、基地项目等意向的同学主动联系加入我们，一起做有趣的研究！本研究组欢迎你的到来！

本课题组2024年计划招收1-2名博士生(已确定)，2-3名硕士研究生（学硕本校本研贯通已招满，专硕尚有2个名额），欢迎物理学和微电子相关领域学生推免或者报考本课题组！！

团队负责人介绍

柴国志，男，博士，兰州大学，物理科学与技术学院，二级教授，“萃英学者”（三级），凝聚态物理博士生导师，电子科学与技术硕士生导师。入选国家级青年人才计划，是甘肃省领军人才、甘肃省杰出青年基金获得者。目前主持国家自然科学基金面上项目1项，其他项目2项；近年来主持完成国家自然科学基金3项，其他各类项目5项。是Scientific Reports杂志凝聚态物理领域编委成员和《磁性材料及器件》青年编委。在Physical Review B、Applied Physics Letters等国际知名刊物上发表SCI论文89篇（截止2024年3月，总被引频次1183次，H因子为19）。曾获得首届教育部“博士研究生学术新人奖”，入选兰州大学“优秀博士学位论文培育项目”。目前主要从事基于布里渊散射的磁振子行为、微波光子-磁振子耦合、高频磁性材料、磁性功能器件等方面的研究。

兰州大学物理科学与技术学院 - 教授

2019年12月 / 今

兰州大学物理科学与技术学院 - 副教授

2014年05月 / 2019年11月

2017年负责购置搭建布里渊光散射仪一台。主要从事高频磁性薄膜中的转动磁各向异性和磁振子光子相互作用性相关的研究工作。

兰州大学物理科学与技术学院 - 讲师

2013年10月 / 2014年04月

主要从事抗电磁干扰软磁薄膜的电磁匹配研究（国家自然科学基金委青年基金项目）。

National University of Singapore - Research Scientist

2012年11月 / 2013年10月

这段时间主要研究了CoFeBSm薄膜中的转动各向异性以及利用其调控材料的高频磁性。在期间参与了C.K.Ong教授研究组微波近场扫描成像系统（NSMM）设备的搭建。

National University of Singapore - Associate Scientist

2012年02月 / 2012年11月

主要研究了NiZn铁氧体掺杂CoFe薄膜中的转动各向异性以及其产生机理。期间学习了C.K.Ong教授课题组内的光子晶体测试平台的使用。

兰州大学物理科学与技术学院 - 硕博连读研究生

2006年09月 / 2012年06月

在薛德胜教授指导下完成了6年的硕博连读研究工作，毕业论文题目为《异质结构软磁材料的高频磁特性研究》，获得了凝聚态物理专业理学博士学位。

兰州大学物理科学与技术学院 - 本科生

2002年09月 / 2006年06月

期间就读于兰州大学物理科学与技术学院物理学国家基地班，2006年06月获得物理学（磁学）理学学士学位。

河北省邢台市第一中学 - 高中

1999年09 / 2002年06月

期间就读于邢台市第一中学。

16. Xiling Li, Yuping Yao, Fusheng Ma, Jianbo Wang, Guozhi Chai, Mode transformation of dynamic spin wave well modes in the magnetic stripes, Applied Physics Letters, 124: 062408 2024.

15. Keke Ma, Chaozhong Li, Zhenhui Hao, C. K. Ong, Guozhi Chai, Strong magnon-magnon coupling between ferromagnetic resonances in Co90Zr10/Ta/Fe20Ni80 multilayers, Physical Review B, 108：094422 2023.

14. C. Q. Liu, Y. B. Zhang, G. Z. Chai, Y. Z. Wu, Large anisotropic Dzyaloshinskii-Moriya interaction in CoFeB(211)/Pt(110) films, Applied Physics Letters, 118：262410 2021.

13. Yongzhang Shi, Chi Zhang, Changjun Jiang, C. K.Ong, Guozhi Chai, Mirror symmetric nonreciprocity and circular transmission in cavity magnonics, Applied Physics Letters, 119: 132403 2021.

12. Wenjie Song, Xiansi Wang, Chenglong Jia, Xiangrong Wang, Changjun Jiang, Desheng Xue, Guozhi Chai, Nonreciprocal emergence of hybridized magnons in magnetic thin films. Phys. Rev. B, 104: 014402, 2021.

11. Chi Zhang, Chenglong Jia, Yongzhang Shi, Changjun Jiang, Desheng Xue, C. K. Ong, and Guozhi Chai, Nonreciprocal multimode and indirect couplings in cavity magnonics. Phys. Rev. B, 103: 184427, 2021.

10. Wenjie Song, Xiansi Wang, Wenfeng Wang, Changjun Jiang, Xiangrong Wang, Guozhi Chai, Backward Magnetostatic Surface Spin Waves in Coupled Co/FeNi Bilayers. physica status solidi (RRL)–Rapid Research Letters, 14: 2000118, 2020.

9. Chi Zhang, Yongzhang Shi, Weihua Zhang, Changjun Jiang and Guozhi Chai, Ultra-strong magnon-photon coupling induced in the photonic crystals with an YGaGeIG defect. Applied Physics Letters, 115(2): 022407, 2019.

8. Wenqiang Wang, Pingping Li, Cuimei Cao, Fufu Liu, Rujun Tang, Guozhi Chai and Changjun Jiang, Temperature dependence of interlayer exchange coupling and Gilbert damping in synthetic antiferromagnetic trilayers investigated using broadband ferromagnetic resonance. Applied Physics Letters, 113(2): 042401, 2018.

7. Dongshan Zhang, Wenjie Song and Guozhi Chai, Spin-wave magnon-polaritons in a split-ring resonator/single-crystalline YIG system. J. Phys. D: Appl. Phys. 50, 205003 (2017).

6. Chengyi Li, Guozhi Chai*, Chengcheng Yang, Wenfeng Wang and Desheng Xue. Tunable Zero-Field Ferromagnetic Resonance Frequency from S to X Band in Oblique Deposited CoFeB Thin Films. Scientific Reports, 5: 17023, 2015.

5. Guozhi Chai*, Nguyen N. Phuoc, and C. K. Ong, Angular tunable zero-field ferromagnetic resonance frequency in oblique sputtered CoFeBSm thin films. Applied Physics Express 7(6): 063001-4, 2014.

4. Guozhi Chai*, Nguyen N. Phuoc, and C. K. Ong. High thermal stability of zero-field ferromagnetic resonance above 5 GHz in ferrite-doped CoFe thin films. Applied Physics Letters, 103(4): 042412-5, 2013.

3. Guozhi Chai, Nguyen N. Phuoc, and C. K. Ong*, Exchange coupling driven omnidirectional rotatable anisotropy in ferrite doped CoFe thin film. Scientific Reports. 2: 832-5, 2012.

2. Guozhi Chai, Yuancai Yang, Jingyi Zhu, Min Lin, Wenbo Sui, Dangwei Guo, Xiling Li, and Desheng Xue*. Adjust the resonance frequency of (Co90Nb10/Ta)n multilayers from 1.4 to 6.5 GHz by controlling the thickness of Ta interlayers. Applied Physics Letters, 96(1): 012505-3, 2010.

1. Guozhi Chai, Desheng Xue*, Xiaolong Fan, Xiling Li, and Dangwei Guo. Extending the Snoek’s limit of single layer film in (Co96Zr4/Cu)n multilayers. Applied Physics Letters, 93(15):152516, 2008.

项目情况

主持各类项目累计11项，其中甘肃省杰出青年基金1项，国家自然科学基金4项。

国家自然科学基金面上项目

2022.1-2025.12 “基于布里渊光散射的磁子非互易行为研究”(NO:12174165)（60万）

甘肃省杰出青年基金

2021.1-2023.12 “微波频段磁拓扑结构动力学行为研究”(NO:20JR10RA649)

国家自然科学基金面上项目

2019.1-2022.12 “高频磁性材料在微波下的磁子-光子耦合机制研究” (No.51871117) (60万)

国家自然科学基金面上项目

2015.1-2018.12 “具有可转动磁各向异性磁性薄膜的GHz下高磁导率机制研究” (No. 51471080) (82万)

国家自然科学基金青年项目

2012.1-2014.12 “抗电磁干扰薄膜材料的电磁匹配研究” (No. 51107055) (25万)

中科院微小卫星创新研究院

2019.1-2019.12 “引力波飞行器磁场分布模拟仿真” (18.9万)

教育部博士生学术新人奖

2010.7-2011.12 “软磁多层薄膜的高频磁特性”(3万)

天津市东丽区政府科技计划

2011.8-2012.7 “微波器件用软磁多层膜材料的研究” (1.5万)

兰州大学中央高校基本科研业务费专项基金

2014.1-2015.6 “磁性薄膜微波磁导率的近场探测装置” (lzujbky-2014-40) (4万)

兰州大学中央高校基本科研业务费优秀研究生创新项目

2010.6-2012.5 “软磁多层膜的静态和动态磁性研究” (lzujbky-2010-219) (1.5万)

兰州大学优博培育项目

2011.1-2012.6 “异质结构软磁材料的高频磁特性研究”

研究工作

于2017年搭建了布里渊光散射仪器（BLS）。BLS实验中光子和磁振子发生非弹性散射时的关系如图所示。当入射光与样品表面有特定夹角时，所激发出的自旋波的波矢与入射光波矢在样品面内的投影呈线性关系，因此可以通过改变入射光与样品表面夹角来改变所探测的自旋波波矢大小。实验中用λ=532nm的单模激光器激发自旋波，磁振子面内波矢与激光入射角度的关系为q = 4πsinθ/λ，因此可以通过改变激光的入射角，来探测不同面内波矢的磁振子行为。然后再同时改变外加磁场的强度，即可得到高频磁性材料中磁振子在磁场和波矢下的色散关系。目前已经完成多层膜中的界面DMI表征、后向表面波、非互易磁振子磁振子耦合等研究。2021年申请到国家自然科学基金支持。

非互易的Magnon-Magnon耦合

在该工作中，主要利用布里渊光散射的方法研究了单层磁性材料NiFe薄膜中出现的PSSW磁子和MSSW磁子非互易的Magnon-Magnon耦合现象。在磁性薄膜中，当MSSW和PSSW这两种波的频率非常接近时，就会产生能级排斥的耦合现象。通过改变NiFe薄膜的厚度，我们在单层磁性薄膜中实现了可控的Magnon-Magnon耦合。实验结果表明这种单层膜中的磁子-磁子耦合是非互易的，表现为耦合后的MSSW和PSSW模式形成偶极-交换自旋波，并分别在薄膜平面内相反的两个界面传输，其结果如图所示。随后通过微磁模拟的方法可以定量地重现实验结果。论文发表在Phys. Rev. B 2021, 104, 014402。

双层磁性膜中的后向表面波

在本工作中利用双层膜中的边界条件不对称在坡莫合金薄膜中实现了群速度为负的表面自旋波，即后向表面波。论文发表在Phys. Status Solidi RRL 2020, 2000118。

异质结构中的DMI研究

利用静磁表面波的色散非互易可以确定磁性异质结构薄膜中的界面DM相互作用，右图所示为本课题组与复旦大学吴义政教授课题组合作发表的在单晶Pt上生长的CoFeB薄膜中的各向异性DMI研究。论文发表在Appl. Phys. Lett. 2021, 118, 262410。与清华大学赵永刚教授合作发现在多铁异质结构薄膜中利用磁电耦合可以实现电场调控的斯格明子[Nat. Commun. 12, 322 (2021)]。BLS磁振子谱用于定量测试Pt/Co/Ta/PMNPT异质结在不同电场下的DMI数值，为解释其中斯格明子的产生和湮灭提供更多的实验证据支持。

由于高频磁性材料在实际应用中是作为磁性器件使用，因此必须对电磁波与高频磁性材料的自旋动力学相互作用进行深入研究。而在特定条件下电磁波（微波光子）与高频磁性材料的高频响应（Magnon，磁振子，磁子）会发生类似腔量子电动力学的强耦合。研究这类强耦合有望使我们更深入理解电磁波和自旋波的相互作用机理以及将基于自旋波的高频磁性器件进一步拓展到应用领域提供理论和实验指导。基于此，我们采用开口谐振环研究了自旋驻波和微波光子系统之间的磁振子光子耦合[JPD 50 205003]，并通过调控开口环的微波磁矢量分布实现了耦合强度的调控[JPD 52, 305003]。在光子晶体系统里，通过铁氧体缺陷实现了腔光子和磁振子的超强耦合[APL 115 022407]。并于2018年申请到国家自然科学基金面上项目支持开展相关研究。

非互易的Photon-Magnon耦合

磁振子-光子耦合中发现了自旋波磁振子和光子的非互易耦合现象，并提出了自旋波磁振子和铁磁共振磁振子间的间接耦和模型。在该工作中，通过将一块单晶钇铁石榴石 (yttrium iron garnet，简称YIG)圆片放在特殊谐振腔的特定位置，进行微波光子和磁振子的相互作用研究。图8实验结果表明，在选定的光子频率下，磁振子和光子耦合时具有明显的非互易现象。随后的实验中，我们除了得到一个耦合强度为0.23 GHz的铁磁共振模式与腔光子模式发生的耦合外，还发现了铁磁共振模式磁振子和高阶的自旋波模式磁振子之间发生的间接耦合，其媒介为谐振腔的光子。为了更好地理解这一现象，我们给出了矩阵方程来预测该系统中磁振子模式通过腔光子模式的间接耦合特性，进而修改了两态耦合模型。该工作为建立两个不相关的磁振子模之间的联系提供了一种方式。论文发表在 Phys. Rev. B 2021, 103, 184427。

光子晶体中的Photon-Magnon耦合

通过将光子晶体中的一个铜柱替换为一个等大的YCaGeIG柱，我们在实验上实现了一个引入磁性点缺陷的光子晶体的微波光子模式与磁性材料的铁磁共振模式的超强相干耦合，耦合强度达到了2.1GHz，占到光子模式能量的大约23.4%。进一步的研究表明，这种超强耦合来自于YCaGeIG柱的大自旋数，耦合强度服从标度率。这给工作表明光子晶体是研究腔-磁振子极化的一种理想材料。除此之外，这个工作也证明了由于磁振子光子耦合，系统磁损耗引起的峰频可以在外加场的变化下在一个大范围内调整。[Appl. Phys. Lett. 115, 022407 (2019)]。

开口环平面谐振器中的Magnon-Photon耦合

采用开口谐振环研究了自旋驻波和微波光子系统之间的磁振子光子耦合耦合强度的调控 [JPD 50 205003]。，并通过调控开口环的微波磁矢量分布实现了耦合强度的调控 [JPD 52, 305003]。。

本人在具有单轴各向异性的高频磁性薄膜方面的研究主要有：在CoZr/Cu多层膜中提高了材料的Snoek极限[APL 93，152516]；在CoNb/Ta多层膜中利用层间交换作用调控了薄膜的各向异性和共振频率[APL, 96, 012505]，并在其他体系中验证了该方法的普适性[IEEE Magn, 47, 3115, JAP 117, 063901, J. Alloy. Compd., 584, 171]；在CoFeB薄膜中实现了共振频率的大范围调控[Sci Rep, 5, 17023]；在CoFe（NiZnFeO）符合薄膜中诱导出了各向异性并得到了好的高频磁性[JPD 42, 205006],利用多铁材料的电场调控实现了共振频率的调控[APL, 114, 112402]；利用三明治结构薄膜实现了GHz频段内各向同性的高磁导率和高共振频率[Sci. Rep. 6, 21327, 授权国家发明专利 ZL 201510393656.9]。

随后在具有可转动磁各向异性的高频薄膜体系中进行了如下研究：在具有条纹畴结构的FeCo 基薄膜中可以将具有条纹畴结构的铁磁薄膜的可转动各向异性场提高到200-300 Oe，相应的共振频率可以高于5GHz [APL, 103, 042412，JPD 46, 415001]。在不具有交换偏置作用的FeNi/FeMn双层膜中发现了其转动各向异性大于单轴各向异性的特点从而实现了面内类各向同性的高频高磁导率[JPD 50, 365003]。在铁磁/亚铁磁颗粒膜中可以诱导出更高的可转动磁各向异性，可以达到200-300Oe。相应的自然共振频率可以达到4.5GHz以上[Sci. Rep. 2, 832]。在Fe4N单层膜中发现了大的可转动各向异性[J alloy Compd 777, 1191]。结合单轴各向异性的特点和可转动磁各向异性，在单层膜材料中实现了不同角度下具有不同共振频率和磁导率的功能性高频薄膜[Appl. Phys. Express 7, 063001]。

在最近研究了异质结构薄膜中的非一致共振现象，例如在Co/FeNi双层膜中研究了光学支共振随层间交换作用的变化关系[JPD 50, 365003]；在FeNi/Ru/FeNi人工反铁磁结构中研究了温度对高频阻尼的影响[APL 113, 042401]；在条纹畴结构CoZr薄膜中研究了非一致共振和畴间交换作用的关系[JPD 51 285004]。

In-plane Isotropic Microwave Performance of CoZr Trilayer in GHz Range

In this work, we investigate the high frequency performance of Co90Zr10/SiO2/Co90Zr10 trilayers. It is demonstrated that the in-plane isotropic microwave performance is theoretically derived from the solution of the Landau-Lifshitz-Gilbert equation and experimentally achieved in that sandwich structured film. The isotropic microwave performance can be tuned to higher resonance frequency up to 5.3 GHz by employing the oblique deposition technique.

Tunable zero-field ferromagnetic resonance frequency from S to X band in oblique deposited CoFeB thin films

We performed an investigation of the static and high frequency magnetic properties for oblique sputtered CoFeB thin films. The static magnetic results revealed that oblique sputtered CoFeB thin films possess well defined in-plane uniaxial magnetic anisotropy, which increases monotonically from 50.1 to 608.8 Oe with the increasing of deposition angle from 10° to 70°. Continuous modification of the resonance frequency of CoFeB thin films in a range of 2.83–9.71 GHz (covers three microwave bands including S, C and X bands) has been achieved.

发展了一套磁性薄膜的高温测试方法[Meas Sci Technol 28, 115104, 授权国家发明专利 ZL. 201610537853.8]。发展了一套X波段高温磁导率测试装置。

A designed shorted microstrip probe for detecting the temperature dependence high frequency permeability of magnetic thin films

A temperature dependence characterization system of microwave permeability of magnetic thin film up to 10 GHz in the temperature range from room temperature up to 200 °C is designed and fabricated. It is based on a designed one-port shorted microstrip probe made by microwave printed circuit board (PCB) for detecting the high frequency permeability of magnetic thin films without limitations in sample size. Without contacting the magnetic thin films to the probe, the microwave permeability of the film can be detected with almost as the same accuracy by comparing with the shorted microstrip transmission-line fixture. The complex permeability can be deduced by an analytical approach from the measured reflection coefficient of a strip line (S11) with and without a ferromagnetic film material on it. The procedures are the same with the shorted microstrip transmission-line method. The microwave permeability of an oblique deposited CoZr thin film was investigated with this probe. The room temperature permeability results of the CoZr film agree well with results obtained from the established short-circuited microstrip perturbation method. Temperature dependence permeability results fit well with the Landau–Lifshitz–Gilbert equation. Developments of the temperature dependent measurement of magnetic properties of the magnetic thin film are important to the high frequency applications of magnetic devices at high temperatures.

发表论文

Up to 15th Mar. 2024, I have published 88 papers with 13 in Appl. Phys. Lett., 8 in Phys. Rev., 3 in Nat. Commun. Total citations are 1183, with h index as 19 (data from Web of Science).

Selected Publications

16. Xiling Li, Yuping Yao, Fusheng Ma, Jianbo Wang, Guozhi Chai, Mode transformation of dynamic spin wave well modes in the magnetic stripes, Applied Physics Letters, 124: 062408 2024.

14. C. Q. Liu, Y. B. Zhang, G. Z. Chai, Y. Z. Wu, Large anisotropic Dzyaloshinskii-Moriya interaction in CoFeB(211)/Pt(110) films, Applied Physics Letters, 118：262410 2021.

13. Yongzhang Shi, Chi Zhang, Changjun Jiang, C. K.Ong, Guozhi Chai, Mirror symmetric nonreciprocity and circular transmission in cavity magnonics, Applied Physics Letters, 119: 132403 2021.

7. Dongshan Zhang, Wenjie Song and Guozhi Chai, Spin-wave magnon-polaritons in a split-ring resonator/single-crystalline YIG system. J. Phys. D: Appl. Phys. 50, 205003 (2017).

5. Guozhi Chai*, Nguyen N. Phuoc, and C. K. Ong, Angular tunable zero-field ferromagnetic resonance frequency in oblique sputtered CoFeBSm thin films. Applied Physics Express 7(6): 063001-4, 2014.

3. Guozhi Chai, Nguyen N. Phuoc, and C. K. Ong*, Exchange coupling driven omnidirectional rotatable anisotropy in ferrite doped CoFe thin film. Scientific Reports. 2: 832-5, 2012.

1. Guozhi Chai, Desheng Xue*, Xiaolong Fan, Xiling Li, and Dangwei Guo. Extending the Snoek’s limit of single layer film in (Co96Zr4/Cu)n multilayers. Applied Physics Letters, 93(15):152516, 2008.

2024

3. Feng X, Bai H, Fan X, Guo M, Zhang Z, Chai G, Wang T, Xue D, Song C and Fan X, Incommensurate Spin Density Wave in Antiferromagnetic RuO₂ Evinced by Abnormal Spin Splitting Torque. 2024 Physical Review Letters 132 086701

2. Li X, Yao Y, Ma F, Wang J and Chai G, Mode transformation of dynamic spin wave well modes in the magnetic stripes. 2024 Applied Physics Letters 124 062408

1. Wang Y, Zhang Y, Li C, Wei J, He B, Xu H, Xia J, Luo X, Li J, Dong J, He W, Yan Z, Yang W, Ma F, Chai G, Yan P, Wan C, Han X and Yu G, Ultrastrong to nearly deep-strong magnon-magnon coupling with a high degree of freedom in synthetic antiferromagnets. 2024 Nature communications 15 2077

2023

4. Ma K, Li C, Hao Z, Ong C K and Chai G, Strong magnon-magnon coupling between ferromagnetic resonances in Co₉₀Zr₁₀/Ta/Fe₂₀Ni₈₀ multilayers. 2023 Physical Review B 108 094422

3. Meng D, Chen S, Ren C, Li J, Lan G, Li C, Liu Y, Su Y, Yu G, Chai G, Xiong R, Zhao W, Yang G and Liang S, Field-Free Spin-Orbit Torque Driven Perpendicular Magnetization Switching of Ferrimagnetic Layer Based on Noncollinear Antiferromagnetic Spin Source. 2023 Advanced Electronic Materials 2300665

2. Wang J, Li M, Li C, Tang R, Si M, Chai G, Yao J, Jia C and Jiang C, Piezostrain-controlled magnetization compensation temperature in ferrimagnetic GdFeCo alloy films. 2023 Physical Review B 107 184424

1. Wang Z, Wang D, Liu L, Jiang S, Chai G, Cao J and Xing G, Tilted magnetic anisotropy-tailored spin torque nano-oscillators for neuromorphic computing. 2023 Applied Physics Letters 123 204101

2022

9. Che J, Zhang X, Zhang W, Dietz B and Chai G, Fluctuation properties of the eigenfrequencies and scattering matrix of closed and open unidirectional graphs with chaotic wave dynamics. 2022 Physical Review E 106 014211

8. Fu S, Xue K, Chai G, Xu Y, Shang T, Cheng W, Jiang D and Zhan Q, Positive stretching dependence of resonance frequency in CoFeB films modulated by lateral growth pre-strain. 2022 Journal of Alloys and Compounds 926 166955

7. Jin Y, Tian Y, Wu H, Zhang Y, Li C, Liu F, Chai G and Jiang C, Magnon dynamics during phase transitions in FeRh by Brillouin light scattering. 2022 Journal of Physics D-Applied Physics 55 355301

6. Li X, Qiao L, Shi H, Chai G, Wang T and Wang J, Temperature denpendent microwave absorption properties of SrFe₁₂O₁₉ in X-band. 2022 Frontiers in Materials 9 1054725

5. Miao P-X, Wang T, Shi Y-C, Gao C-X, Cai Z-W, Chai G-Z, Chen D-Y and Wang J-B, Measurement of coercivity of soft magnetic materials in open magnetic circuit by pump-probe rubidium atomic magnetometer. 2022 Acta Physica Sinica 71 244206

4. Wang J, Li C, Tang R, Chai G, Yao J and Jiang C, Spin-orbit torque in a single ferrimagnetic GdFeCo layer near the compensation temperature. 2022 Applied Physics Letters 120 102402

3. Zhang C, Zhang S, Ma T, Chai G and Wang T, Improvement of high-frequency magnetic properties in antiferromagnetic coupling trilayers by easy-plane magnetocrystalline anisotropy. 2022 Journal of Magnetism and Magnetic Materials 561 169708

2. Zhang Q, Liang J, Bi K, Zhao L, Bai H, Cui Q, Zhou H-A, Bai H, Feng H, Song W, Chai G, Gladii O, Schultheiss H, Zhu T, Zhang J, Peng Y, Yang H and Jiang W, Quantifying the Dzyaloshinskii-Moriya Interaction Induced by the Bulk Magnetic Asymmetry. 2022 Physical Review Letters 128 167202

1. Zhang Y, Kong X, Xu G, Jin Y, Jiang C and Chai G, Direct observation of the temperature dependence of the Dzyaloshinskii-Moriya interaction. 2022 Journal of Physics D-Applied Physics 55 195304

2021

1. Cao C, Chen S, Song W, Zhu X, Hu S, Qiu X, Chai G, Sun L, Cheng W, Jiang D and Zhan Q, Spin-orbit torque and Dzyaloshinskii-Moriya interaction in 4d metal Rh-based magnetic heterostructures. 2021 Applied Physics Letters 118 112402

2. Che J, Lu J, Zhang X, Dietz B and Chai G, Missing-level statistics in classically chaotic quantum systems with symplectic symmetry. 2021 Physical Review E 103 042212

3. Huang M, Gao L, Zhang Y, Lei X, Hu G, Xiang J, Zeng H, Fu X, Zhang Z, Chai G, Peng Y, Lu Y, Du H, Chen G, Zang J and Xiang B, Possible Topological Hall Effect above Room Temperature in Layered Cr_1.2Te₂ Ferromagnet. 2021 Nano Letters 21 4280

4. Kang C, Wang T, Jiang C, Chen K and Chai G, Investigation of the giant magneto-impedance effect of single crystalline YIG based on the ferromagnetic resonance effect. 2021 Journal of Alloys and Compounds 865 158903

5. Li C-Z, Jiang C-J and Chai G-Z, Angular control of multi-mode resonance frequencies in obliquely deposited CoZr thin films with rotatable stripe domains. 2021 Chinese Physics B 30 037502

6. Liu C Q, Zhang Y B, Chai G Z and Wu Y Z, Large anisotropic Dzyaloshinskii-Moriya interaction in CoFeB(211)/Pt(110) films. 2021 Applied Physics Letters 118 262410

7. Liu F, Zhou C, Tang R, Chai G and Jiang C, Continuously Controllable Charge-Spin Conversion by Electric Fields in FeNi/Pt/Pb(Mg_1/3Nb_2/3)O₃-Pb_{0.7Ti_0.3O₃ Heterostructures. 2021 Physica Status Solidi-Rapid Research Letters 15 2100342}

8. Liu F, Zhou C, Tang R, Chai G and Jiang C, Controllable charge-spin conversion by Rashba-Edelstein effect at Cu/Ta interface. 2021 Journal of Magnetism and Magnetic Materials 540 168462

9. Liu J, Chen J, Zhang Y, Fu S, Chai G, Cao C, Zhu X, Guo Y, Cheng W, Jiang D, Zhao Z and Zhan Q, Stretching-Tunable High-Frequency Magnetic Properties of Wrinkled CoFeB Films Grown on PDMS. 2021 ACS Applied Materials & Interfaces 13 29975

10. Liu X, Song W, Wu M, Yang Y, Yang Y, Lu P, Tian Y, Sun Y, Lu J, Wang J, Yan D, Shi Y, Sun N X, Sun Y, Gao P, Shen K, Chai G, Kou S, Nan C-W and Zhang J, Magnetoelectric phase transition driven by interfacial-engineered Dzyaloshinskii-Moriya interaction. 2021 Nature Communications 12 5453

11. Shi Y, Zhang C, Jiang C, Ong C K and Chai G, Mirror symmetric nonreciprocity and circular transmission in cavity magnonics. 2021 Applied Physics Letters 119 132403

12. Song W, Wang X, Jia C, Wang X, Jiang C, Xue D and Chai G, Nonreciprocal emergence of hybridized magnons in magnetic thin films. 2021 Physical Review B 104 014402

13. Wang J, Li C, Ma L, Liu F, Chai G and Jiang C, Nonvolatile electric-field-controlled anomalous Hall effect in ferrimagnetic GdFeCo film. 2021 Journal of Physics D-Applied Physics 54 075001

14. Wang J, Li C, Wang Y, Tang R, Chai G and Jiang C, Giant modulation of magnetic compensation temperature in ferrimagnetic GdFeCo alloys by oblique sputtering. 2021 Applied Surface Science 567 150527

15. Wang Y, Li C, Zhou H, Wang J, Chai G and Jiang C, Unusual anomalous Hall effect in the ferrimagnetic GdFeCo alloy. 2021 Applied Physics Letters 118 071902

16. Zhang B, Wu L, Feng X, Wang D, Chi X, Chai G, Yang P, Ding J, Han J, Chen J, Zhu Y and Chow G M, Re-entrance to a ferromagnetic insulator with oxygen-vacancy ordering in the La_0.7Sr_0.3MnO₃/SrTiO₃ superlattice. 2021 Journal of Materials Chemistry A 9 26717

2020

1. Gao, Yang; Tian, Yinhua; Zhang, Yabing; Chai, Guozhi*; Study of the intensity asymmetry in Brillouin light scattering from magnons in FeNi thin films, Journal of Magnetism and Magnetic Materials, 2020, 504: 166671.

2. Qi, Ji; Dong, Baojuan; Zhang, Zhe; Zhang, Zhao; Chen, Yanna; Zhang, Qiang; Danilkin, Sergey; Chen, Xi; He, Jiaming; Fu, Liangwei; Jiang, Xiaoming; Chai, Guozhi; Hiroi, Satoshi; Ohara, Koji; Zhang, Zongteng; Ren, Weijun; Yang, Teng; Zhou, Jianshi; Osami, Sakata; He, Jiaqing; Yu, Dehong*; Li, Bing*; Zhang, Zhidong; Dimer rattling mode induced low thermal conductivity in an excellent acoustic conductor., Nature Communications, 2020, 11(1): 5197.

3. Zhang, Wanling; Zhang, Jiaming; Wu, Peng; Chai, Guozhi; Huang, Ran; Ma, Fei; Xu, Fangfang; Cheng, Hongwei; Chen, Yonghui; Ni, Xia; Qiao, Liang; Duan, Jinglai; Parallel Aligned Nickel Nanocone Arrays for Multiband Microwave Absorption., ACS Appl Mater Interfaces, 2020, 12(20): 23340-23346.

4. Song, Wenjie; Wang, Xiansi; Wang, Wenfeng; Jiang, Changjun; Wang, Xiangrong; Chai, Guozhi; Backward Magnetostatic Surface Spin Waves in Coupled Co/FeNi Bilayers, Physica Status Solidi-Rapid Research Letters, 2020, 14(8): 2000118.

2019

1. Zhang, Runzu; Zhang, Weihua; Dietz, Barbara*; Chai, Guozhi; Huang, Liang; Experimental investigation of the fluctuations in nonchaotic scattering in microwave billiards, Chinese Physics B, 2019, 28(10): 100502.

2. Wang, Tao; Kang, Chen; Chai, Guozhi*; Low-Frequency Noise Evaluation on a Commercial Magnetoimpedance Sensor at Submillihertz Frequencies for Space Magnetic Field Detection., Sensors (Switzerland), 2019, 19(22).

3. Pan, Lulu; Wang, Wenfeng; Wang, Wentao; Zhang, Peng; Xi, Li; Chai, Guozhi*; Xue, Desheng*; Rotatable anisotropy in Fe4N thin film with quasi-single magnetic domain, Journal of Alloys and Compounds, 2019, 777: 1191-1196.

4. Cao, Cuimei; Shen, Lvkang; Chen, Shiwei; Yang, Kunya; Lan, Guohua; Li, Pingping; Wang, Wenqiang; Liu, Ming; Chai, Guozhi*; Jiang, Changjun*; Reciprocal-space-resolved piezoelectric control of non-volatile magnetism in epitaxial LiFe5O8film on Pb(Mg1/3Nb2/3)0.7Ti0.3O3substrate, Applied Physics Letters, 2019, 114(11): 112402.

5. Wang, Yangping; Liu, Fufu; Cao, Cuimei; Zhou, Cai*; Chai, Guozhi; Jiang, Changjun*; Ionic-liquid gating controls anomalous hall resistivity of Co/Pt perpendicular magnetic anisotropy films, Journal of Magnetism and Magnetic Materials, 2019, 491: 165626.

6. Zhang, Chi; Shi, Yongzhang; Zhang, Weihua; Jiang, Changjun; Chai, Guozhi*; Ultra-strong magnon-photon coupling induced in the photonic crystals with an YGaGeIG defect, Applied Physics Letters, 2019, 115(2): 022407.

7. Shi, Yongzhang; Zhang, Dongshan; Zhang, Chi; Jiang, Changjun; Chai, Guozhi*; Control of photon-magnon coupling with a nonuniform microwave magnetic field, Journal of Physics D: Applied Physics, 2019, 52(30): 305003.

8. Li, Xi Ling; Wang, Jian Bo; Chai, Guo Zhi*; Techniques of microwave permeability characterization for thin films, Chinese Physics B, 2019, 28(9): 097504.

9. 柴国志; 黄亮; 乔亮; 张冠茂; 星上剩磁对惯性传感器的影响, 中国光学, 2019, 12(3): 515-525.

2018

1. Huige Ma, Chengyi Li, Wenfeng Wang and Guozhi Chai1, Thickness-dependent resonance frequency of non-uniform procession mode in CoZr stripe-domain magnetic films. J. Phys. D: Appl. Phys. 51, 285004 (2018).

2. Wenqiang Wang, Pingping Li, Cuimei Cao, Fufu Liu, Rujun Tang, Guozhi Chai, and Changjun Jiang, Temperature dependence of interlayer exchange coupling and Gilbert damping in synthetic antiferromagnetic trilayers investigated using broadband ferromagnetic resonance. Applied Physics Letters. 113, 042401 (2018).

3. Cunxu,Gao ; Yu,Miao ;Yutian,Wang ; Guozhi ,Chai,;Peng,Chen, ; Desheng,Xue, Interface-induced spiral magnetic structure of epitaxial Fe films on GaAs(001). Aip Advances. 8, 125026 (2018).

2017

1. Wenfeng Wang, Guozhi Chai and Desheng Xue, Omnidirectional zero-field ferromagnetic resonance driven by rotatable anisotropy in FeNi/FeMn bilayers without exchange bias. Sci Rep. 7, 1341 (2017).

2. Dongshan Zhang, Wenjie Song and Guozhi Chai, Spin-wave magnon-polaritons in a split-ring resonator/single-crystalline YIG system. J. Phys. D: Appl. Phys. 50, 205003 (2017).

3. Wenfeng Wang, Guozhi Chai* and Desheng Xue*, Thickness dependent optical mode ferromagnetic resonance in Co/FeNi bilayer. J. .Phys. D: Appl. Phys. 50, 365003 (2017)

4. Xiling Li, Chengyi Li, Guozhi Chai*, Temperature dependence of dynamical permeability characterization of magnetic thin films using shorted microstrip line probe , Measurement Science and Technology, 28, 115104 (2017)

2016

1. Lulu Pan, Fenglong Wang, Wenfeng Wang, Guozhi Chai* and Desheng Xue*. In-plane Isotropic Microwave Performance of CoZr Trilayer in GHz Range. Scientific Reports, 6: 21327, 2016.

2015

1. Zhiling Wang, Xiaolong Fan*, Xiaobing Zhao, Guozhi Chai, Desheng Xue, Fabrication of Co90Zr10 thin films with adjustable resonance frequency from 1.8 to 7.1 GHz. Journal of Alloys and Compounds, 628: 236-239, 2015.

2. Cunxu Gao, Yutian Wang*, Chengyi Li, Yanping Wei, Zhendong Chen, Guozhi Chai and Desheng Xue, Multidirectional available high-frequency response with zero-field resonance above 8 GHz in epitaxial α-Fe(001) films. Applied Physics Express 8(5): 053001-3, 2014.

3. Guozhi Chai*, Xinhua Wang, Zhiling Wang and Desheng Xue, Tunable microwave magnetic properties in oblique deposited CoHf/Ta multilayers. Journal of Applied Physics, 117(6): 063901-5, 2015.

4. X. D. Jiang, D. W. Guo, C. H. Zhang, X. L. Fan, G. Z. Chai and D. S. Xue*. Influence of the Interface on the Magnetic Properties of Nizn Ferrite Thin Films Treated by Proton Irradiation. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 358: 1-5, 2015.

5. Chengyi Li, Guozhi Chai*, Chengcheng Yang, Wenfeng Wang and Desheng Xue. Tunable Zero-Field Ferromagnetic Resonance Frequency from S to X Band in Oblique Deposited CoFeB Thin Films. Scientific Reports, 5: 17023, 2015.

2014

1. Xiaoxi Zhong*, Nguyen N. Phuoc, Guozhi Chai, Ying Liu, C.K. Ong, Thermal stability and dynamic magnetic properties of FeSiAl films fabricated by oblique deposition. Journal of Alloys and Compounds, 610: 126-131, 2014.

2. Guozhi Chai*, Nguyen N. Phuoc, and C. K. Ong, Angular tunable zero-field ferromagnetic resonance frequency in oblique sputtered CoFeBSm thin films. Applied Physics Express 7(6): 063001-4, 2014.

3. Xinhua Wang, Guozhi Chai*, and Desheng Xue*, Magnetic properties of (Co92Zr8/SiO2)15 multilayer thin films for GHz applications. Journal of Alloys and Compounds, 584: 171-174, 2014.

4. Wee Tee Soh, Bin Peng, Guozhi Chai, and C. K. Ong*, Note: Electrical detection and quantification of spin rectification effect enabled by shorted microstrip transmission line technique. Review of Scientific Instruments, 85: 026109-3, 2014.

2013

1. Guozhi Chai*, Xinhua Wang, M. S. Si, Desheng Xue, Adjustable microwave permeability of nanorings: A micromagnetic investigation. Physics Letters A, 377(21-22): 1491-1494, 2013.

2. Nguyen N. Phuoc*, Wee Tee Soh, Guozhi Chai, and C. K. Ong, Investigation of magnetic properties and microwave characteristics of obliquely sputtered NiFe/MnIr bilayers. Journal of Applied Physics, 113(7): 073902-6, 2013.

3. Guozhi Chai*, Nguyen N. Phuoc, and C. K. Ong. High thermal stability of zero-field ferromagnetic resonance above 5 GHz in ferrite-doped CoFe thin films. Applied Physics Letters, 103(4): 042412-5, 2013.

4. Gaoxue Wang, Chunhui Dong, Zhongjie Yan, Tao Wang, Guozhi Chai, Changjun Jiang*, and Desheng Xue. Controlling of magnetic domain structure by sputtering films on tilted substrates. Journal of Alloys and Compounds, 573: 118-121, 2013.

5. Guozhi Chai*, Nguyen N. Phuoc, and C. K. Ong. Optimizing high-frequency properties of stripe domain ferrite doped CoFe thin films by means of a Ta buffer layer. Journal of Physics D: Applied Physics 46(4): 415001-7, 2013.

2012

1. Guozhi Chai, Nguyen N. Phuoc, and C. K. Ong*, Exchange coupling driven omnidirectional rotatable anisotropy in ferrite doped CoFe thin film. Scientific Reports. 2: 832-5, 2012.

2. Nguyen N. Phuoc*, Guozhi Chai, and C. K. Ong, Temperature-dependent dynamic magnetization of FeCoHf thin films fabricated by oblique deposition. Journal of Applied Physics, 112(8): 083925-6, 2012.

3. Nguyen N. Phuoc*, Guozhi Chai, and C. K. Ong, Enhancing exchange bias and tailoring microwave properties of FeCo/MnIr multilayers by oblique deposition. Journal of Applied Physics, 112(11): 113908-6, 2012.

4. Gaoxue Wang, Chunhui Dong, Changjun Jiang*, Guozhi Chai, Desheng Xue, Effect of nanoparticle size on magnetic damping parameter in Co92Zr8 soft magnetic films. Journal of Magnetism and Magnetic Materials, 324(18): 2840-2803, 2012.

5. Gaoxue Wang, Chunhui Dong, Wenxi Wang, Zhiling Wang, Guozhi Chai, Changjun Jiang*, and Desheng Xue, Observation of rotatable stripe domain in permalloy films with oblique sputtering. Journal of Applied Physics, 112(9): 093907-4, 2012.

6. Xu Yan, Daqiang Gao, Guozhi Chai, Desheng Xue*, Adjustable microwave absorption properties of flake shaped (Ni0.5Zn0.5)Fe2O4/Co nanocomposites with stress induced orientation. Journal of Magnetism and Magnetic Materials, 324(11):1902-1906, (2012).

2011

1. Xu Yan, Guozhi Chai, and Desheng Xue*, The improvement of microwave properties for Co flakes after silica coating. Journal of Alloys and Compounds, 509(4): 1310-1313, 2011.

2. Wenbo Sui, Jingyi Zhu, Jinyun Li, Guozhi Chai, Changjun Jiang, Xiaolong Fan, and Desheng Xue*, Determination of the anisotropies and reversal process in exchange-bias bilayers using a rotational magnetization curve approach. Journal of Applied Physics, 109(10): 103902-6, 2011.

3. Guozhi Chai, Dangwei Guo, Xiaolong Fan and Desheng Xue*, Microwave magnetic properties of soft magnetic thin films. Science China Physics, Mechanics & Astronomy. 54(7): 1200-1207, 2011

4. Guozhi Chai, Zhiling Wang, Gaoxue Wang, Wenbo Sui, and Desheng Xue*, Adjustable Microwave Properties in FeCoZr/Cu Multilayers. IEEE Transactions on Magnetics. 47(10): 3115-3117, 2011.

2010

1. Guozhi Chai, Nguyen N. Phuoc, and C. K. Ong*, Exchange coupling driven omnidirectional rotatable anisotropy in ferrite doped CoFe thin film. Scientific Reports. 2: 832-5, 2012.

2. Dangwei Guo, Xiaolong Fan, Guozhi Chai, Changjun Jiang, Xiling Li, and Desheng Xue*. Structural and magnetic properties of NiZn ferrite films with high saturation magnetization deposited by magnetron sputtering. Applied Surface Science, 256(8): 2319-2322, 2010.

3. Dangwei Guo, Jingyi Zhu, Yuancai Yang, Xiaolong Fan, Guozhi Chai, Wenbo Sui, Zhengmei Zhang, and Desheng Xue*. High-frequency magnetic properties of Zn ferrite films deposited by magnetron sputtering. Journal of Applied Physics, 107(4): 043903, 2010.

4. Zhengmei Zhang, Min Lin, Jingyi Zhu, Dangwei Guo, Guozhi Chai, Xiaolong Fan*, Yuancai Yang, and Desheng Xue*. Effect of light rare earth element Nd doping on magnetization dynamics in Co-Nb films. Journal of Applied Physics, 107(8): 083912, 2010.

5. Zhengmei Zhang, Xiaolong Fan*, Min Lin, Dangwei Guo, Guozhi Chai, and Desheng Xue*. Optimized soft magnetic properties and high frequency characteristics of obliquely deposited Co-Zr thin films. Journal of Physics D: Applied Physics, 43(8): 085002, 2010.

2009

1. Guozhi Chai, Dangwei Guo, Xiling Li, Jingyi Zhu, Wenbo Sui, and Desheng Xue*. Magnetic properties of (Co0.65Fe0.35 )1-x(Ni0.5 Zn0.5 Fe2 O4 )x bi-magnetic composite granular films for high frequency application. Journal of Physics D: Applied Physics, 42(20):205006, 2009.

2. Xi-Ling Li, Guo-Zhi Chai, Dang-Wei Guo, Bo Gao, Zheng-Mei Zhang, and De-Sheng Xue*. Increasing the thin film inductance by using soft magnetic Co92Zr8 as conductor. Microelectronic Engineering, 86(11):2290, 2009.

3. Dangwei Guo, Zhengmei Zhang, Min Lin, Xiaolong Fan, Guozhi Chai, Yan Xu, and Desheng Xue*. Ni-Zn ferrite films with high resonance frequency in the gigahertz range deposited by magnetron sputtering at room temperature. Journal of Physics D: Applied Physics, 42(12):125006, 2009.

2008

1. Guozhi Chai, Desheng Xue*, Xiaolong Fan, Xiling Li, and Dangwei Guo. Extending the Snoek’s limit of single layer film in (Co96Zr4/Cu)n multilayers. Applied Physics Letters, 93(15):152516, 2008.

2. Desheng Xue, Guozhi Chai*, Xiling Li, and Xiaolong Fan, Effects of grain size distribution on coercivity and permeability of ferromagnets. Journal of Magnetism and Magnetic Materials, 320(8):1541, (2008).

团队成员

截止2023.9.01，共有在读博士生5名，硕士生11名，已毕业博士4名，硕士11名。获研究生国家奖学金2人次，CPS优秀海报奖3人次，优秀毕业生1人次。请点开查看个人详细信息。

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诚聘英才

诚邀国内外优秀青年研究人员、博士后、应届博士毕业生加入本课题组!

本课题组依托兰州大学磁学与磁性材料教育部实验室，以国家青年人才计划入选者柴国志教授为课题负责人，团队目前有兼聘外籍教授1名，工程师1名。主要研究内容如下：

基础研究：主要围绕微波矢量网络分析仪和布里渊光散射两个设备，结合低温超导磁体微波探针台、自主搭建Locked-in FMR、室温孔超导磁体和近场光学显微镜等开展磁性材料的高频动力学相关研究。目前的主要研究方向为：磁振子-微波光子耦合中的非厄米系统基本物理、耦合强度调控、非互易行为；自旋波动力学中的自旋波非互易、磁振子-磁振子耦合和非共线磁结构中自旋波的色散关系；自旋电子学输运测试结合微波测试研究自旋波的传输和调制。

应用研究: 面向国家重大需求，结合高频磁性材料和高频磁动力学开展磁功能器件研究。主要集中在磁场传感器、微波非互易器件等方面。

招聘岗位：

教授/研究员、副教授/副研究员、青年研究员、萃英博士后

基本要求：

具有优秀的工作基础和较大发展潜力，与课题组研究方向相关，有事业心和责任感，有与课题组共同进步的强烈意愿。

具体条件和待遇请参考：物理科学与技术学院招聘公告。

联系方式：

请将简历发送至：柴国志，chaigzh@lzu.edu.cn

本课题组2023年计划招生2-3名硕士研究生，欢迎物理学和微电子学相关领域学生推免或者报考本课题组！！

1.磁传感器测试标定方法

2.磁传感器电路设计

3.磁性微丝反磁化动力学过程模拟