Yan, Li
213 Holden Hall, Virginia Tech, Blacksburg,
VA, 24061
540-921-7131(cell phone) lyan@vt.edu
Summary:
Ø Deposit ferroelectric and ferromagnetic
epitaxial thin films using Physical Vapor Deposition (PVD);
Ø Measure and analyze thin films using XRD, AFM
(PFM, MFM), SEM, and dielectric, ferroelectric, piezoelectric and magnetic
instruments;
Ø Build and maintain PLD system, ferroelectric
and piezoelectric measurement system;
Ø Design, optimize, fabricate and measure
piezoelectric actuator, sensors and MEMS devices.
Education:
Ph.D., Materials Science and Engineering, Virginia Tech, VA, expected summer 2009
(Prof. D. Viehland)
M.S., Materials Science and Engineering, Tsinghua University, Beijing, China,
2003 (Prof. Li Longtu)
B.E., Materials Science and Engineering, Tsinghua University, Beijing, China,
2000 (Prof. Dong Shuxiang)
Projects:
Multi-ferroic Thin Films, 2003-Present (funded by DOE, Air-Force and ONR):
§ Multi-ferroic
properties, nano-structures and growth mechanism in BiFeO3-CoFe2O4
and BaTiO3-CoFe2O4 composite epitaxial thin
films (for the first time measured the direct Magnetoelectric coupling in
perovskite-spinel self-assembled epitaxial nano-composite thin films, and for
the first time observed nano-belt structures in that system) ;
§ Low symmetry
phases in BiFeO3, Pb(Zr,Ti)O3 thin films by epitaxial
engineering using special oriented single crystal substrates (for the first
time deposited and observed the triclinic and monoclinic C phases in BiFeO3
and PZT epitaxial thin film respectively) ;
§ Relaxor behavior
and weak ferromagnet of Pb(Fe1/2N1/2)O3
epitaxial thin films, dramatically increase the ferroelectricity by constraint
stress of the substrates (Increased the polarization of Pb(Fe1/2N1/2)O3
by a factor of 3, which makes it a good candidate in industry application) ;
§ Nano growth twin
and enhanced ferromagnetic properties in CoFe2O4 thin
films (for the first time observed the nano-twin structure and abnormal
ferromagnetic properties in spinel materials) ;
Piezoelectric Micro-motors and Devices, 2000-Present (funded by ONR, NASA
and Chinese NSF):
§ Φ3mm novel
wobbling piezoelectric micro motor, the first rod-shaped axle out-put
ultrasonic micro motor;
§ Φ2mm rod piezoelectric
micro motor, one of the smallest among contemporary ultrasonic motors;
§ Low temperature
high torque disk-shaped piezoelectric single crystal motor (cooperation);
§ Multi-claw low
temperature piezoelectric motor, new concept with extra redundancy for movement
(cooperation);
§ Small linear
piezoelectric ultrasonic cryomotor, working at lower temperature (cooperation);
§ Drum-shaped
piezoelectric H2 sensor (cooperation);
§ Bimorph layer
Magnetoelectric sensor (cooperation).
§ Disk-shaped
piezoelectric distance sensor for automobile (cooperation).
Semiconductor Processing and MEMS Fabrication, 2005-2006:
§ MOSFETs and Resistors devices design, build
and measurement in clean room.
§ Travelling wave
Micro-motor design and simulation by MEMS techniques.
Systems Built:
o
High
vacuum high temperature chambers for Pulsed Laser Deposition;
o
D33
measurement system for thin film by PFM, signal generator, amplifier and
lock-in amplifier;
o
Ferroelectric
measurement system for thin film by signal generator, amplifier, and oscilloscope;
o
Low
temperature low vacuum H2 sensor measurement system;
o
Linear
crymotor measurement system with nano measurement ability.
Skills:
Instruments:
·
Main
user of Pulsed Laser Deposition system and Lamda 305i Laser for
deposition of 8 kinds of epitaxial thin films (>3000 hours);
·
Main
user of Phillips X’pert X-Ray, Scintac X-Ray for phase analysis
and structure measurement of epitaxial thin films and ceramics (>3000
hours);
·
Main
user of Dimension 3100 Scanning Probe Microscope for AFM, PFM and MFM
measurement of multi-ferroic single phase and nano-composite thin films
(>1500 hours);
·
Main
user of Polytec OFV056 Vibro-meter for measurement of vibration of
piezoelectric micro devices;
·
Qualified
user of Quantum Design SQUID for magnetic measurement of ferromagnetic
thin films;
·
Qualified
user of Cobilt Mask Aligner for semiconductor processing;
·
User of
Radiant Technology Precision Workstation for the electric measurement of
ferroelectric thin films;
·
User of
HP4294, HP4284…… for all kinds or electric measurement of piezoelectric,
ferroelectric, dielectric properties.
Software:
·
Algor used to analysis and optimize piezoelectric
micro-motors and micro actuators by FEA method;
·
AutoCAD used to design ultrasonic micro-motor, parts
in PLD chamber, and build crystal structure model of low symmetry phase in
epitaxial thin films;
·
LabView used to do the piezoelectric (d33) measure
by PFM and external signal generator;
·
L-Edit used to design the processing for thin layer
devices.
Publications
[1] Yan
L, Xing ZP, Wang ZG, Wang T, Lei GY, Li JF, Viehland D, Direct Measurement of Magnetoelectric Exchange in
Self-Assembled Epitaxial BiFeO3-CoFe2O4
Nano-Composite Thin films, APPLIED PHYSICS LETTERS 94 (19): 192902 (2009)
[2] Yan
L, Zhao X, Li JF, Viehland D, Enhancement of
multi-ferroic properties of Pb(Fe1/2Nb1/2)O3
thin films on SrRuO3 buffered SrTiO3 substrate by
epitaxial stress, APPLIED PHYSICS LETTERS 94 (19): 192903 (2009)
[3]
Yan L, Cao H, Li JF, Viehland D, Triclinic
phase in tilted (001) oriented BiFeO3 epitaxial thin films, APPLIED
PHYSICS LETTERS 94 (13): 132901
(2009)
[4]
Yan L, Bai FM, Li JF, Viehland D, Nano-structures
in perovskite-ferrite two phase composite epitaxial thin films, PHILOSOPHICAL MAGAZINE: DOI: 10.1080/14786430902967702
(2009)
[5] Yan
L, Yang YD, Wang ZG, Li JF, Viehland D, Review
of magnetoelectric perovskite–spinel self-assembled nano-composite thin films, JOURNAL OF
MATERIALS SCIENCE: DOI 10.1007/s10853-009-3679-1 (2009)
[6] Yan
L, Bai FM, Li JF, Viehland D, Nano-belt
structure in perovskite-spinel composite thin films, JOURNAL OF THE AMERICAN CERAMIC SOCIETY 92: 17 (2009)
[7] Dong SX, Yan L, Viehland
D, Jiang XN, Hackenberger W, A piezoelectric single crystal
traveling wave step-motor for low-temperature application, APPLIED PHYSICS LETTERS 92 (15): 153504 (2008)
[8]
Yan L, Wang Y, Li JF, Pyatakov A, Viehland D, Nano
growth twins and abnormal magnetic behavior in CoFe2O4
epitaxial thin films, JOURNAL OF APPLIED PHYSICS 104:
123910 (2008)
[9] Yan L, Li JF, Viehland
D, Structure of (001), (110), and (111) oriented
Pb(Fe1/2Nb1/2)O3 epitaxial thin films on SrRuO3
buffered SrTiO3 substrates, JOURNAL OF MATERIALS RESEARCH 23: 663 (2008)
[10] Yan L, Li JF, Viehland
D, Deposition conditions and electrical properties
of relaxor ferroelectric Pb(Fe1/2Nb1/2)O3 thin
films prepared by pulsed laser deposition, JOURNAL OF APPLIED PHYSICS 101: 104107 (2007)
[11] Yan L, Li JF, Cao H,
and Viehland D, Low symmetry phase in Pb(Zr0.52Ti0.48)O3
epitaxial thin film with enhanced ferroelectric properties,
APPLIED PHYSICS LETTERS 89 (26):
262905, (2006)
[12] Yan L, Li JF,
Suchicital C, and Viehland D, Multiferroic
epitaxial Pb(Fe1/2Nb1/2)O3 thin films: A
relaxor ferroelectric/weak ferromagnet with a variable structure, APPLIED
PHYSICS LETTERS 89 (13): 132913
(2006)
[13] Xing ZP, Dong SX, Zhai JY, Yan L, Li JF, Viehland D, Resonant bending mode of
Terfenol-D/Steel/Pb(Zr,Ti)O3 magnetoelectric laminate composites, APPLIED PHYSICS LETTERS 89 (11): 112911, (2006)
[14] Dong SX, Yan L, Wang NG, Viehland D, Jiang XN, Rehrig P and Hackenberger W, A small, linear, piezoelectric
ultrasonic cryomotor, APPLIED
PHYSICS LETTERS 86 (5): 053501,
(2005)
[15] Dong SX, Bai FM, Yan L, Cao H, Li JF and Viehland D, Vacuum response and gas leak
detection in piezoelectrically driven sound-resonance cavity, APPLIED PHYSICS LETTERS 84 (21): 4144-4146, (2004)
[16] Dong SX, Cao H, Bai FM, Yan L, Li JF, Viehland D and Gao YK, Conformal sensor skin approach
to the safety-monitoring of H-2 fuel tanks, APPLIED PHYSICS LETTERS 84
(21): 4153-4154, (2004)
[17] Chu XC, Yan L and Li LT, Characteristic analysis of an
ultrasonic micromotor using a 3 mm diameter piezoelectric rod, SMART MATERIALS & STRUCTURES 13 (2): N17-N23, (2004)
[18] Yan L, Chu XC, Dong SX and Li LT, Piezoelectric ceramic
vibration modes and potential applications, KEY ENGINEERING MATERIALS 224-2:
129-134, (2002)
[19] Chu XC, Yan RB, Yan L, Li LT, A quantitative circuit model
of the stator of piezoelectric ultrasonic motor, KEY ENGINEERING MATERIALS 224-2: 135-138, (2002)
[20] Yan
L, Chu XC, Dong SX, Li LT, Progress of piezoelectric micro-motor, PIEZOELECTRICS AND ACOUSTOOPTICS 24-2:
116-121, (2001)
[21] Chu XC, Yan L and Li
LT, Study of φ1.8mm rod shaped piezoelectric
ceramic micro-motor,
PIEZOELECTRICS AND ACOUSTOOPTICS 23-2: 103-105, (2001)
[22] Yan L, Chu XC and Li
LT, Study of φ2mm rod shaped piezoelectric ceramic
micro-motor, MATERIALS REVIEW
special vol: 178-179, (2000)
Conferences:
[1] Yan L, Li JF and
Viehland D, Magnetoelectric Eptaxial Thin Layer Two Phase Composites, MS&T, 2008 (Invited Talk)
[2] Yan L, Fabrication
Issues of Oxide Thin Films, MS&T, 2008 (Session Chair).
[3] Yan L, Li JF and
Viehland D, Nano-belt Structures and Formation Mechanism of BaTiO3-CoFe2O4
Thin film, MRS Fall, 2007
(Poster)
[4] Yan L, Li JF, Cao H and
Viehland D, Monoclinic Phase and Ferroelectric Properties in Pb(Zr0.52Ti0.48)O3
Epitaxial Thin Films on (110) Oriented SrTiO3 Substrates, MRS Fall, 2007 (Poster)
[5] Yan L, Li JF and
Viehland D, Deposition and Properties of Multiferroic Epitaxial Pb(Fe1/2Nb1/2)O3
Thin films by Pulsed Laser Deposition, MRS Fall, 2006 (Talk)
Patents
[1] Li LT, Yan L, Chu XC and
Dong SX, Axle-powered rod type piezoelectric ceramic micro-motor, patent number: CN03146160.5, 2003 (in
China)
[2] Li LT, Yan L, Chu XC and
Gui ZL, Multi-degree freedom composite-driven rod type piezoelectric
ceramic micro-motor, pantent
number: CN03146162.X, 2003 (in China)