Probing Ferroelectricity, Charge Density Wave Dynamics, and Magnetism with Submicron X-ray Diffraction Paul G. Evans Department of Materials Science and Engineering ...
aps.anl.gov/news/meetings/aps_cross_cut_reviews/2004/presentations/evans.pdf
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Text Previews (text result may be not accurate) •Brief Introduction to MicrobeamExperiments at
•Overview: Physical Phenomena and Motivation
•In Depth:
UltrafastLaser Facility
Coherent small angle scattering.
MR sample is rigidly mounted while
SawtoothLi Lens
E. M.Dufresne,
•6 to 30 keV
•10
•Minimum spot (APS, sector 2)-
-0.4
-0.2
0.2
0.4
-300-200-1000100200300
(220) reflection
(004) reflection
substrate (220)
rocking curve peak
shift (deg.)
position (
bridge
•Brief Introduction to MicrobeamExperiments at
•Overview: Physical Phenomena and Motivation
•In Depth:
-8000-6000-4000-200002000
T-PZT(200)
R-PZT(002)
T-PZT(002)
SRO(220)
STO(002)
Count/20s
Position(sec)
PZT 0.08
angle relative to STO (002) (sec.)
Piezoelectric
Electrical
!
Diamond Demonstration Version
2
00
(
Switching with X-ray Microdiffraction
!
m
!
-10-50510
100
120
140
P
-10 V
!
m
1
100
1
100
2000
2500
3000
100
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
time
34.62
34.72
34.82
34.92
35.02
w
e
h
t
e
-10-50510
Piezoelectric Distortion
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
time
34.62
34.72
34.82
34.92
35.02
w
e
h
t
e
Polarization Fatigue: 160 nm, ±10 V
cycles, ±10 V
1.Fatigue in PZT devices with Pt electrodes pins the polarization
2.Fatigue at
1.X-ray microdiffraction provides a new avenue to studying
2.Quantitative agreement of x-ray observations with electrical
3.Potential to take advantage of the flexibility of x-ray scattering
•Domains are responsible for macroscopically observable
(
q
)
K
K
q
K
E
E
1
)
(
+
q
in wavevector by
.
H
E
E
H
H
E
H
H
!
!
!
-e
-e
-e
K
incident
beam
diffracted
beam
ˆ
ˆ
(
'
k
k
S
.
,
+
)
0.4
0.6
0.8
1.2
0.040.060.080.1
intensity (a.u.)
(2+
,0,0)
(0,2+
,0)
(0,0,2+
Domain populations
H : K : L
4.65 : 1.35 : 1
0.950.9530.956
0
=5.8 keV
0
Transverse SDW phaseLongitudinal SDW phase
2
4
|| (001)
(001)
10
10
Q
8.7
110120130140
mean intensity
(counts s
10
10
10
140 K
130 K
125 K
119 K
115 K
2
4
and
(001)
K
H
Q
transverse phase
•Self organized or artificial domains at small scales are
•Spin flip transition in Cr begins at domain walls upon
•Future work in Cr:
–Control of domain walls
–Separation of bulk and interface effects
Probing Ferroelectricity Charge Density Wave Dynamics And