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Dr. CHEN Yunjie

Scientist III

Staff

Advanced Characterisation and Instrumentation (ACI) Department

67149084

chen_yunjie@imre.a-star.edu.sg

2 Fusionopolis Way, Innovis, #08-03, Singapore 138634


Research Details


- Materials Characterization and Failure Analysis (SPM; XRD; SEM/STEM/EDS)
- Magnetic recording and materials
- Ion-surface interaction
- Nano science and technology

 

- Scanning probe microscopy (SPM): STM,AFM,MFM,EFM, KFPM, TUNA, CAFM, SSRM, SCM, NSOM, Nanoindentation
- Thin film growth: Sputtering, MBE, laser ablation
- Magnetic materials characterization: AGM, VSM, MOKE, SQUID
- Magnetic recording performance test: hands-on spinstand testing

 

2013-2015: Project co-PI “Study of magnetic switching behavior and switching field distribution in nano-patterned magnetic structures and devices”, “MOKE study of the dynamic behaviors of domain wall in magnetic nanostructures”, Phase I&II, Joint project DSI-NTU.
2010-2013: Project co-PI “Nano Patterning, All-Optical Recording, and Pattern Media Magnetics”, Joint project IMRE-DSI.
2009-2013: Member “Read-Write and testing of ‘Thin Drive’ disk media”, “Static Read/Write of Patterned Media”, Industry project with Hitachi High Technology (HHT).
2008-2009: Project Leader “Bit patterned media”, INSIC (US) grant.
2007-2010: Project Leader “Discrete bit patterned media (DBPM) recording physics, recording performance test and recording subsystem integration”, Joint project DSI-NUS.
2004: Project Leader “Low Cost DTR Patterned Media By Nanoimprint”, Joint project DSI-IMRE.
2000-2004: Project Leader “Oriented media for high density magnetic recording”, DSI core project.

 

Key Appointments:

2018-present: Scientist III, Advanced Characterisation and Instrumentation, IMRE
2016-2018: Scientist III, Materials Science Lab (MSL) Division, DSI
2012-2016: Scientist III, Drive System and Technology (DST) Division, DSI
2011-2012: Senior Manager, Advanced media R&D, Western Digital Corporation (WD)
2007-2011: Research Scientist I/II, Spintronics, Media, & Interfaces (SMI) Division, DSI
2005-2007: Staff Engineer, Recording Performance Engineering, Seagate Technology
2000-2005: Senior Research Engineer, Magnetic Materials and Media, DSI
1999-2000: Postdoctoral Fellow, Dept. of Materials Science and Engineering, National University of Singapore
1998-1999: Postdoctoral Fellow, Information Storage Materials Laboratory (ISML), Toyota Technological Institute (Japan)

Services:

2013-2017: Ph. D student co-supervisor, NTU
2009-2013: Ph. D student co-supervisor, NUS
2003-2006: Post-graduate student co-supervisor, NUS
2008 : Ph. D candidate thesis examiner, NTU
2011: InterMag 2011, Session HG, Conference session chair (Session HG)
2009-2010: DSI project review committee member
2008: DSI social committee member
2004: DSI equipment management task force member
1998-present: Manuscript Reviewer, Applied Physics Letters

 

Ph.D, Chinese University of Hong Kong, Electronics Engineering, 1997

 

DSI Best Paper Award (2005 Q1)

 

2018: Vice Chair, Institute of Electrical and Electronics Engineers (IEEE) Magnetics Singapore Chapter
2017: Secretory, Institute of Electrical and Electronics Engineers (IEEE) Magnetics Singapore Chapter
2017: Member, Institute of Electrical and Electronics Engineers (IEEE), Senior Member Review Panel
2009 – present: Senior Member, Institute of Electrical and Electronics Engineers (IEEE), US
2004 – 2009: Member, Institute of Electrical and Electronics Engineers (IEEE), US
2006: Six Sigma Brown Belt (Seagate Technology)
1998: Member, Magnetic Society of Japan
1997: Member, Hong Kong Material Research Society
1996: Member, Material Research Society, US

 

55. "Measurement of magnetic property of FePt granular media at near Curie temperature", H. Z. Yang, Y. J. Chen, S. H. Leong, C. W. An, K. D. Ye, and J. F. Hu, J. Magn. Magn. Mater. 423, 27-33 (2017). (Published online 14/Sept/2016).
54. "FePt based HAMR media with a function layer for better thermal control", J. F. Hu, Kiat Min Cher, Binni Varghese, Baoxi Xu, Chee Beng Lim, Jianzhong Shi, Y. J. Chen, Kaidong Ye, Jing Zhang, Chengwu An, and Wen Huei Tsai, IEEE Trans. Magn. 52, 3200306 (2016).
53. "Quick fabrication of appropriate morphology and composition CoFe films with desirable microwave properties", B. Y. Zong, Y. P. Wu, Nguyen Phuoc, P. Ho, J. J. Qiu, Y. Yang, M. J. Chua, W. B. Ng, Y. J. Chen, and G. C. Han, Int. J. Mater. Res. 106e, pp. e1-e9 (2015).
52. "Direct observation of deterministic domain wall trajectory in magnetic network structures", P. Sethi, C. Murapaka, S. Goolaup, Y. J. Chen, S. H. Leong, and W. S. Lew, Scientific Reports 6, 19027 (2016).
51. "Preparation and characterization of dedicated servo media", Jianzhong Shi, Hang Khume Tan, Hanxiang Ng, Zhimin Yuan, Chun Lian Ong, Shiming Ang, Jiangfeng Hu, Yi Yang, Yunjie Chen, Ng Kang Kee, Seet Hang Li, Lim Chee Beng, Lam Suet Hoi, and Jack Tsai, IEEE Trans. Magn. 52, 3200604 (2016).
50. "An experimental investigation on Curie temperature (Tc) variations and related switching field distributions (SFD) in heat assisted magnetic recording (HAMR) media", Y. J. Chen, S. H. Leong, H. Z. Yang, and J. F. Hu, IEEE Trans. Magn. 51, 3201504 (2015).
49. "Calibration and measurement of the thermal reflection coefficient of heat assisted magnetic recording media", H. Z. Yang, Y. J. Chen, S. H. Leong, C. W. An, K. D. Ye, M. J. Yin, and J. F. Hu, Metrologia. 52, pp. 502-508 (2015).
48. "Erasure Temperature measurements of heat assisted magnetic recording (HAMR) media", Y. J. Chen, H. Z. Yang, S. H. Leong, K. M. Cher, J. F. Hu, P. Sethi, and W. S. Lew, J. Appl. Phys. 117, 17D117 (2015).
47. "Heat assisted recording on bottom layer of dual recording layer perpendicular magnetic recording media for two and a half dimensional (2.5D) magnetic data storage", Y. J. Chen, H. Z. Yang, S. H. Leong, B. Santoso, J. Z. Shi, B. X. Xu, and J. W. H. Tsai, J. Appl. Phys. 117, 17C106 (2015)
46. "A study on dynamic heat assisted magnetization reversal mechanisms under insufficient reversal field conditions", Y. J. Chen, H. Z. Yang, S. H. Leong, B. L. Wu, M. Asbahi, Hnin Yu Ko, J. K. W. Yang, and V. Ng, Appl. Phys. Lett. 105, 162402 (2014).
45. "Direct observation of domain wall evolution at a bifurcation in magnetic network structures", M. Chandra Sekhar, P. Sethi, S. Goolaup, M. Ramu, Y. J. Chen, S. H. Leong, and W. S. Lew, Appl. Phys. Express. 7, 113003 (2014).
44. "Perpendicular magnetic clusters with configurable domain structures via dipole–dipole interactions", W. M. Li, S. K. Wong, T. S. Herng, L. K. Yap, C. H. Sim, Z. C. Yang, Y. J. Chen, J. Z. Shi, G. C. Han, J. M. Xue, and J. Ding, Nano Research Vol. 8 (issue 11), pp. 3639-3650 (2015). (Published online 13/Oct/2015).
43. "Fabrication of thin soft films with appropriate nanomorphology and composition to achieve desirable static magnetism and dynamic microwave properties for high frequency applications", B. Y. Zong, Y. P. Wu, Nguyen Phuoc, P. Ho, J. J. Qiu, Y. Yang, M. J. Chua, W. B. Ng, Y. J. Chen, and G. C. Han, submitted to J. Magn. Magn. Mater. (2014).
42. "A multi-functional testing instrument for HAMR media", H. Z. Yang, Y. J. Chen, S. H. Leong, C. W. An, K. D. Ye, M. J. Yin, and J. F. Hu, J. Appl. Phys. 115, 07B917 (2014).
41. "Fabrication of ultrahigh density metal–cell–metal crossbar memory devices with only two cycles of lithography and dry-etch procedures", B. Y. Zong, J. Y. Goh, Z. B. Guo, P. Luo, C. C.Wang, J. J. Qiu, P. Ho, Y. J. Chen, M. S. Zhang, and G. C. Han, Nanotechnology 24, 245033 (2013).
40. "Thermoreflection Measurement of Magnetic Thin Films", H. Z. Yang, S. H. Leong, C. W. An, Y. J. Chen, K. D. Ye, L. T. Ng, J. Zhang, K. K. Ng, and J. F. Hu, IEEE Trans. Magn. 49, 2827 (2013).
39. "Comparison of Bit-Patterned Media Fabricated by Methods of Direct Deposition and Ion-Milling of Cobalt/Palladium Multilayers", N. Thiyagarajah, T. L. Huang, Y. J. Chen, H. G. Duan , D. L. Y. Song , S. H. Leong , J. K. W. Yang, and V. Ng, J. Appl. Phys. 111, 103906 (2012).
38. "Angular dependence and temperature effect on switching field distribution of Co/Pd based bit patterned media", W. M. Li, X. L. Huang, J. Z. Shi, Y. J. Chen, T. L. Huang, and J. Ding, J. Appl. Phys. 111, 07B917 (2012).
37. "Characterization of L10-FePt/Fe based exchange coupled composite bit pattern media", Hao Wang, W. M. Li, M. Tofizur Rahman, Haibao Zhao, J. Ding, Y. J. Chen, and Jian-Ping Wang, J. Appl. Phys. 111, 07B914 (2012).
36. "Study of magnetization reversal of Co/Pd bit-patterned media by micro-magnetic simulation", W. M. Li, Y. Yang, Y. J. Chen, T. L. Huang, J. Z. Shi, and J. Ding, J. Magn. Magn. Mater. 324, 1575 (2012).
35. "Individual bit island reversal and switching field distribution in perpendicular magnetic bit patterned media" (invited), Y. J. Chen, T. L. Huang, J. Z. Shi, J. Deng, J. Ding, W. M. Li, S. H. Leong, B. Y. Zong, Hnin Yu Ko, S. B. Hu, and J. M. Zhao, J. Magn. Magn. Mater. 324, 264 (2012).
34. "Fabrication and characterization of bit-patterned media beyond 1.5 Tbit/in2", J.K.W. Yang, Y. J. Chen, T. L. Huang, H. G. Duan, N. Thiyagarajah, H. K. Hui, S. H. Leong, and V. Ng, Nanotechnology 22, 5301 (2011).
33. "Patterned Media and Energy Assisted Recording Study by Drag Tester", S. H. Leong, J. B. Lim, S. Budi, C. L. Ong, Z. M. Yuan, Y. J. Chen, T. L. Huang, and S. B. Hu, IEEE Trans. Magn. 47, 1981 (2011).
32. "Calculation of individual bit island switching field distribution in perpendicular magnetic bit patterned media", W. M. Li, Y. J. Chen, T. L. Huang, J. M. Xue, and J. Ding, J. Appl. Phys. 109, 07B758 (2011).
31. "Switching probability distribution of bit islands in bit patterned media", Y. J. Chen, J. Ding, J. Deng, T. L. Huang, S. H. Leong, J. Z. Shi, B. Y. Zong, Hnin Yu Ko, C. K. Au, S. B. Hu, and B. Liu, IEEE Trans. Magn. 46, 1990 (2010).
30. "Thermal effects induced lateral head shift of thermal flying height control perpendicular magnetic recording head", Y. J. Chen, S. H. Leong, T. L. Huang, H. W. Ho, V. Ng, and J. C. H. Phang, J. Phys. D: Appl. Phys. Magn. 43, 035001 (published online18/Jan/2010).
29. "Magnetic force microscopy and spinstand testing of multi-row-per-track discrete bit patterned media fabricated by focused ion beam", Y. J. Chen, T. L. Huang, S. H. Leong, S. B. Hu, K. W. Ng, Z. M. Yuan, B. Y. Zong, J. Z. Shi, S. K. Hendra, B. Liu, and V. Ng, J. Appl. Phys. 105, 07C105 (2009).
28. "A study of multirow-per-track bit patterned media by spinstand testing and magnetic force microscopy", Y. J. Chen, T. L. Huang, S. H. Leong, S. B. Hu, K. W. Ng, Z. M. Yuan, B. Y. Zong, B. Liu, and V. Ng, Appl. Phys. Lett. 93, 102501 (2008).
27. "A comparative study of write field distribution of trailing-edge shielded and unshielded perpendicular write heads by quantitative magnetic force microscopy", Y. J. Chen, S. H. Leong, T. L. Huang, K. W. Ng, S. B. Hu, Z. M. Yuan, and V. Ng, Appl. Phys. Lett. 92, 162505 (2008).
26. "A Study of FIB Patterned discrete Track Recording Media by Spinstand Read/Write Testing and Scanning Probe Microscopy", Y. J. Chen, S. H. Leong, K. W. Ng, Z. B. Guo, J. Z. Shi, J. M. Zhao, and B. Liu, J. Magn. Magn. Mater. 303, e141-e144 (2006).
25. "Investigation of temperature rise in GMR sensor and disk induced by laser irradiation", S. B. Hu, B. X. Xu, H. X. Yuan, Y. J. Chen, J. Zhang, and R. Ji, J. Magn. Magn. Mater. 303, e62-e65 (2006).
24. "Thermal Effect on Recording Mark Quality in Heat Assisted Recording", B. X. Xu, H. X. Yuan, S. B. Hu, R. Ji, Y. J. Chen, J. Zhang, X. S, Miao, J. S. Chen, and T. C. Chong, J. Magn. Magn. Mater. 303, e34-e38 (2006).
23. "Thermal effects of heated magnetic disk on slider in Heat-assisted magnetic recording", B. X. Xu, S. B. Hu, H. X. Yuan, J. Zhang, Y. J. Chen, R. Ji, X. S, Miao, J. S. Chen, and T. C. Chong, J. Appl. Phys. 99, 08N102 (2006).
22. "Smooth Discrete Track Media Fabricated by Focused Ion Beam", B. S. H. Pang, Y. J. Chen, and S. H. Leong, Appl. Phys. Lett. 88, 094103 (2006).
21. "A study of origin of orientation ratio in longitudinal magnetic thin film media on plasma treated textured substrates", Y. J. Chen, D. Y. Dai, H. B. Zhao, S. I. Pang, J. H. Yin, L. Wu, T. P. Guan, S. N. Piramanayagam, and J. P. Wang, Appl. Phys. A 81, 147 (2005).
20. "Recording Performance of Discrete Track Patterned Media Fabricated by Focused Ion Beam", Y. J. Chen, K. W. Ng, S. H. Leong, Z. B. Guo, J. Z. Shi, and B. Liu, IEEE Trans. Magn. 41, 2195 (2005).
19. "Dynamic orientation ratio in longitudinal recording media", S. N. Piramanayagam, J. H. Yin, H. B. Zhao, J. Kasim, Y. J. Chen, J. Zhang, and C. H. Hee, Appl. Phys. Lett. 83, 1175 (2003).
18. "Periodic magnetic nanostructures on self-assembled surfaces by ion beam bombardment", Y. J. Chen, J. P. Wang, E. W. Soo, L. Wu, and T. C. Chong, J. Appl. Phys. 91, 7323 (2002).
17. "Magnetic domains and magnetotransport properties in Co-Ag granular thin films", Y. J. Chen, J. Ding, L. Si, W. Y. Cheung, I. H. Wilson, and T. Suzuki, Appl. Phys. A 73, 103 (2001).
16. "SiO2 modified Co-ferrite with high coercivity", J. Ding, H, Gong, R. Melaka, S. Wang, Y. Shi, Y. J. Chen, and N. X. Phuc, J. Magn. Magn. Mater. 226, 1382 (2001).
15. "High coercivity in SiO2-doped CoFe2O4 powders and thin films", J. Ding, Y. J. Chen, Y. Shi and S. Wang, Appl. Phys. Lett. 77, 3621 (2000).
14. "High coercivity in mechanically alloyed BaFe10All2O19", S. Wang, J. Ding, Y. Shi and Y. J. Chen, J. Magn. Magn. Mater. 219, 206 (2000).
13. "Magnetic Properties and Domains in Co-Ag Granular Thin Films", Y. J. Chen, T. Suzuki, and H. Kanazawa, J. Appl. Phys. 87, 4837 (2000).
12. "Ion beam synthesized cobalt germanide alloy by metal vapor vacuum arc implantation", C. S. Lee, I. H. Wilson, W. Y. Cheung, Y. J. Chen, J. B. Xu, and S. P. Wong, Nucl. Instr. Meth. B 148, 604-609 (1999).
11. "Perpendicular magnetic anisotropy and Magneto-Optical Kerr effect in giant magnetoresistive Co-Ag granular thin films", Y. J. Chen, T. Suzuki, Y. Itoh, W. Y. Cheung, and H. Sang, J. Magn. Soc. Jpn. Suppl. 23 (S1), 31 (1999).
10. "Perpendicular magnetic anisotropy of Co22Ag78 granular thin films", Y. J. Chen, T. Suzuki, S. P. Wong, and H. Sang, J. Appl. Phys. 85, 5048 (1999).
9. "Surface roughness and oxide contents of gas-phase and solid-phase polysulfide passivation of III-V surfaces", W. H. Choy, R. W. M. Kwok, B. K. L. So, Y. J. Chen, J. B. Xu, S. P. Wong and W. M. Lau, J. Vac. Sci. Technol. A 17 (1), 93-96 (1999).
8. "An STM and AFM study of the effects of 1.8 MeV electron bombardment on the surface of graphite", Y. J. Chen, I. H. Wilson, J. B. Xu, and Lin Libin, J. Mat. Sci. 33, 4657-4663 (1998).
7. "Magnetic domain structures of Co22Ag78 granular films observed by magnetic force microscopy", Y. J. Chen, W. Y. Cheung, I. H. Wilson, N. Ke, S. P. Wong, H. Sang, and G. Ni, Appl. Phys. Lett. 72, 2472 (1998).
6. "Tip artifacts in atomic force microscope imaging of ion bombarded nanostructures on germanium surfaces", Y. J. Chen, I. H. Wilson, C. S. Lee, J. B. Xu, and M. L. Yu, J. Appl. Phys. 82, 5859 (1997).
5. "A study of ion bombarded nanostructures on germanium surfaces by scanning probe microscopy", Y. J. Chen, W. Y. Cheung, I. H. Wilson, S. P. Wong, and J. B. Xu, Thin Solid Films 308/309, 415-419 (1997).
4. "1.8 MeV electron bombardment induced structural change on graphite surface observed by scanning tunnelling microscopy", Y. J. Chen, I. H. Wilson, Lin Libin, and J. B. Xu, Mat. Res. Soc. Symp. Proc. 439, 703-708 (1997).
3. "Ion implanted nanostructrues on Ge(111) surfaces observed by atomic force microscopy", Y. J. Chen, I. H. Wilson, W. Y. Cheung, J. B. Xu, and S. P. Wong, J. Vac. Sci. Technol. B 15 (4), 809-813 (1997).
2. "Single ion impacts on an In0.22Ga0.78As/GaAs(100) surface observed by atomic force microscopy", I. H. Wilson, Y. J. Chen, and J. B. Xu, Nucl. Instr. Meth. B 124, 500-505 (1997).
1. "Ion impacts and nanostructures on Ge(111), In0.22Ga0.78As/GaAs(100) and alpha quartz surfaces observed by atomic force microscopy", I. H. Wilson, Y. J. Chen, J. B. Xu, R. A. B. Devine, and C. Jeynes, Surf. Interface Anal. 24, 881-886 (1996).

 

YunJie CHEN and Jian Ping Wang, "Manufacturing method for high-density magnetic data storage media", (2003) US patent US20030091865A1.
YunJie CHEN and Jian Ping Wang. "Method for manufacturing method for high-density magnetic data storage media", (2003) Japan patent JP 2003151127A.
YunJie CHEN and Jian Ping Wang, "Manufacturing method for high-density magnetic data storage media", (2004) Singapore patent SG102013A1.
YunJie CHEN and Jian Ping Wang, "Manufacturing method for high-density magnetic data storage media", (2004) US patent US 6719841 B2.
YunJie CHEN, Zhimin Yuan, Siang Huei Leong, Ka Wei Ng, and Bo Liu, "Recording device with write head spanning multiple rows of bit cells and multi-sensor read head", (2010) US patent US2010/0020435A1.
Jie Deng, Yunjie Chen, Jianzhong Shi, Baoyu Zong, TianLi Huang, and Siang Huei Leong,"Method for forming a magnetic recording medium and a magnetic recording medium thereof", (2012) US patent US 2012/0082865 A1.
Yunjie Chen, Siang Huei Leong, and Bo Liu, "Dedicated servo read head for dedicated servo media", (2013) Singapore patent #201304958-0.
Yunjie Chen, Siang Huei Leong, Baoxi Xu, and Hongzhi Yang, "Dual laser HAMR (heat assisted magnetic recording) head", (2016) filed Singapore patent application (#10201602000R).
Yunjie Chen, Siang Huei Leong, and Bo Liu, "Read assembly, data storage system, and methods of using the same", (2014) World Intellectual Property Organization (WIPO) / PCT patent WO 2014209231 A1.
Yunjie Chen, Siang Huei Leong, and Bo Liu, "READ ASSEMBLY, DATA STORAGE SYSTEM, AND METHODS OF USING THE SAME", (2016) US patent US2016/0140989 A1.
Yunjie Chen, Siang Huei Leong, Baoxi Xu, and Hongzhi Yang, "A write device for magnetic media", (2017) World Intellectual Property Organization (WIPO) / PCT patent WO 2017/160230 A1.

 


Last updated on : 05 Apr 2019 06:04 PM