Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources
We investigate different properties of ¹³C diamond layer which was grown on a top of a brilliant cut diamond anvil. We connected equations of state for diamond with stress and strain concentrating on the case of [100], see ([1]) strain with diamond anvil bearing load plane as (100), (see [1]). We in...
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irk-123456789-193702011-04-28T12:04:30Z Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources Kondrat’yev, A.I. Інтелектуальні ресурси. Науково-технологічна безпека We investigate different properties of ¹³C diamond layer which was grown on a top of a brilliant cut diamond anvil. We connected equations of state for diamond with stress and strain concentrating on the case of [100], see ([1]) strain with diamond anvil bearing load plane as (100), (see [1]). We investigated the behavior of optical Г phonons with respect to pressure, strain and stress parameters. We also did simulation of these problems using finite element modeling and Nike2D computer software. We used O.H. Nielsen approach for modeling of the sensor. Досліджуються різноманітні властивості прошарку ¹³C-алмаза, який виростили на верхівці сенсора-діаманта. Поєднані рівняння стану алмаза і концентрації з фоноеластичними властивостями. Досліджуються рівняння, які описують поведінку оптичних фонів в термінах тиску і напруги. Проведено моделювання цих проблем з використанням методу кінцевих елементів і програмного забезпечення Nike2D. Для моделювання сенсору було застосовано метод наближення О. Нільсена. Исследуются различные свойства слоя ¹³C-алмаза, выращенного на вершине сенсора - бриллианта. Объединены уравнения состояния алмаза и концентрации с фоноэластическими свойствами. Исследуются уравнения, описывающие поведение оптических фононов в терминах давления и напряжения. Проведено моделирование этих проблем, используя метод конечных элементoв и программное обеспечение Nike2D. Для моделирования сенсора применен метод приближения О. Нильсена. 2009 Article Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources / A.I. Kondrat’yev // Екологічна безпека та природокористування: Зб. наук. пр. — К., 2009. — Вип. 3. — С. 124-149. — Бібліогр.: 6 назв. — англ. XXXX-0062 http://dspace.nbuv.gov.ua/handle/123456789/19370 502/504 en Екологічна безпека та природокористування Інститут телекомунікацій і глобального інформаційного простору НАН України |
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Інтелектуальні ресурси. Науково-технологічна безпека Інтелектуальні ресурси. Науково-технологічна безпека |
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Інтелектуальні ресурси. Науково-технологічна безпека Інтелектуальні ресурси. Науково-технологічна безпека Kondrat’yev, A.I. Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources Екологічна безпека та природокористування |
description |
We investigate different properties of ¹³C diamond layer which was grown on a top of a brilliant cut diamond anvil. We connected equations of state for diamond with stress and strain concentrating on the case of [100], see ([1]) strain with diamond anvil bearing load plane as (100), (see [1]). We investigated the behavior of optical Г phonons with respect to pressure, strain and stress parameters. We also did simulation of these problems using finite element modeling and Nike2D computer software. We used O.H. Nielsen approach for modeling of the sensor. |
format |
Article |
author |
Kondrat’yev, A.I. |
author_facet |
Kondrat’yev, A.I. |
author_sort |
Kondrat’yev, A.I. |
title |
Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources |
title_short |
Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources |
title_full |
Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources |
title_fullStr |
Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources |
title_full_unstemmed |
Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources |
title_sort |
modeling of phonoelastic and strain-stress properties of ¹³c high pressure sensor for use in ecological safety and use of natural resources |
publisher |
Інститут телекомунікацій і глобального інформаційного простору НАН України |
publishDate |
2009 |
topic_facet |
Інтелектуальні ресурси. Науково-технологічна безпека |
url |
http://dspace.nbuv.gov.ua/handle/123456789/19370 |
citation_txt |
Modeling of Phonoelastic and Strain-stress Properties of ¹³C High Pressure Sensor for Use in Ecological Safety and Use of Natural Resources / A.I. Kondrat’yev // Екологічна безпека та природокористування: Зб. наук. пр. — К., 2009. — Вип. 3. — С. 124-149. — Бібліогр.: 6 назв. — англ. |
series |
Екологічна безпека та природокористування |
work_keys_str_mv |
AT kondratyevai modelingofphonoelasticandstrainstresspropertiesof13chighpressuresensorforuseinecologicalsafetyanduseofnaturalresources |
first_indexed |
2025-07-02T20:12:32Z |
last_indexed |
2025-07-02T20:12:32Z |
_version_ |
1836567392224804864 |
fulltext |
124
Ðîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè.
Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
УДК 502/504
MODELING OF PHONOELASTIC AND STRAIN-STRESS
PROPERTIES OF 13C HIGH PRESSURE SENSOR
FOR USE IN ECOLOGICAL SAFETY
AND USE OF NATURAL RESOURCES
Andreiy I. Kondrat’yev
(Doctor of Physical and Mathematical Sciences (Mathematical
Theory and Applications of Conflict Results Prediction). MS, PhD
(Physics) from University of Alabama at Birmingham, USA)
МОДЕЛИРОВАНИЕ НАГРУЗОК-НАПРЯЖЕНИЙ
И ФОНОЭЛАСТИЧЕСКИХ СВОЙСТВ 13C-СЕНСОРА
ВЫСОКОГО ДАВЛЕНИЯ ДЛЯ ПРИМЕНЕНИЯ
В ЭКОЛОГИЧЕСКОЙ БЕЗОПАСНОСТИ
И ПРИРОДОПОЛЬЗОВАНИИ
А.И. Кондратьев
We investigate different properties of 13C diamond layer which was grown on
a top of a brilliant cut diamond anvil. We connected equations of state for diamond
with stress and strain concentrating on the case of [100], see ([1]) strain with
diamond anvil bearing load plane as (100), (see [1]). We investigated the behavior
of optical Г phonons with respect to pressure, strain and stress parameters. We
also did simulation of these problems using finite element modeling and Nike2D
computer software. We used O.H. Nielsen approach for modeling of the sensor.
Досліджуються різноманітні властивості прошарку 13С-алмаза, який
виростили на верхівці сенсора-діаманта. Поєднані рівняння стану алмаза
Andreiy I. Kondrat’yev, 2009
125
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
і концентрації з фоноеластичними властивостями. Досліджуються
рівняння, які описують поведінку оптичних фонів в термінах тиску і на-
пруги. Проведено моделювання цих проблем з використанням методу кінце-
вих елементів і програмного забезпечення Nike2D. Для моделювання сен-
сору було застосовано метод наближення О. Нільсена.
Исследуются различные свойства слоя 13C-алмаза, выращенного на
вершине сенсора - бриллианта. Объединены уравнения состояния алма-
за и концентрации с фоноэластическими свойствами. Исследуются
уравнения, описывающие поведение оптических фононов в терминах
давления и напряжения. Проведено моделирование этих проблем, исполь-
зуя метод конечных элементoв и программное обеспечение Nike2D. Для
моделирования сенсора применен метод приближения О. Нильсена.
Main Hypothesis. We assume that with initial stress and stress
and compressing load as (100) the compressive changes in diamond
anvils and in high pressure sensor maybe divided in the following
consecutive changes:
1. Initial stresses and strains in [100] direction.
2. Stresses and strains in [110] direction.
3. Stresses and strains in [111] direction.
The resultant are elastic and plastic changes in elastic solids and
they are mixture of stresses and strains in [100], [110] and [111]
directions. As the result the Raman signal will be also the mixture
of the signals of strained cells in each of the directions: [100], [110]
and [111]. Formally all of these maybe written in the following way.
1. For stress tensor components
.1; 111]111[1]110[1]100[1 =γ+β+αγ+β+α= tttt
tttt
2. For strain tensor components
.1; 222]111[2]110[2]100[2 =γ+β+αηγ+ηβ+ηα=η
ttt
3. For phonoelastic tensor components
.1; 333]111[3]110[3]100[3 =γ+β+αΩγ+Ωβ+Ωα=Ω
ttt
126
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
Research Goals include investigation, verification, and modeling
of Diamond Equations of State, Ã Optical Phonon Behavior, High
Pressure Sensor Calibration
Introduction. We study the behavior of à optical phonons in
diamond anvil which are triply degenerate when strain is not present.
When external pressure appears and thus internal strains are present
the diamond cubic symmetry does not exist anymore and this
triplet is split. On Fig.1 the 13C high pressure sensor is presented.
Fig. 1. 13C High Pressure Sensor in the form of a layer on
natural diamond anvil.
Real Problem of Raman Peak Shift. While compressing the
sensor and anvils in DAC at 156 GPa pressure we’ve obtained the
following shift of the Raman signal (see Fig. 2).The most interesting
thing is that the Raman signal from the sensor is widened and at
156 GPa pressure this signal has the width of 21.51 1/cm. The
main goal of this article is to try to analyze this phenomenon and
to try to develop the physical and mathematical models of it. Our
first step is the data analysis. In Table 1 we put all numerical data
of this pressure sensor. We analyze all points on the graph in the
range from 1542 1/cm to 1563 1/cm and the peaks (graphs) associated
with them.
127
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
F
ig
.2
.
R
am
an
S
ig
na
l
fr
om
1
2 C
N
at
ur
al
D
ia
m
on
d
A
nv
ils
a
nd
1
3 C
H
ig
h
P
re
ss
ur
e
S
en
so
r
128
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
Table 1 — Numerical Presentation of the Raman Signal
from High Pressure Sensor
Number of
the Point
Wave
Number
Value(1/cm)
Intensity of
Raman Signal
(ye)
Length of the Interval
associated with the
point (1/cm)
1 1542.18 34977 0.83
2 1543.01 35348 0.82
3 1543.83 35864 0.83
4 1544.66 35472 0.83
5 1545.49 36029 0.83
6 1546.32 35492 0.83
7 1547.15 36133 0.82
8 1547.97 35967 0.82
9 1548.8 36195 0.83
10 1549.63 36216 0.83
11 1550.46 36195 0.82
12 1551.28 35657 0.83
13 1552.11 35719 0.83
14 1552.94 35306 0.83
15 1553.77 36983 0.82
16 1554.59 34977 0.83
17 1555.42 36133 0.83
18 1556.25 35513 0.82
19 1557.07 34997 0.83
20 1557.90 35492 0.83
21 1558.73 36236 0.82
22 1559.55 35059 0.83
23 1560.38 35802 0.83
24 1561.21 36195 0.82
25 1562.03 34586 0.83
26 1562.86 35472 0.83
27 1563.69 34709 0.82
We can see that all relative width for each point signal is about
the same as 0.82–0.83 1/cm.
Our next step is to analyze the local peaks which are parts of this
part of the curve. These local curves (peaks) are described in Table 2.
129
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
Elements of Lagrangian Elastic Theory. There are different ways
to present Lagrangian point of view on Solid Mechanics issues. The
way the most close to our goals is presented in [1].
Within Lagrangian elastic theory for a strain tensor η
t
and t
t
as
a stress tensor we have
2
2
1
ε+ε=η
ttt ,
11 )1()1)(1det( −− ε+σε+ε+=
tttttttt
t .
Number
of the
Peak
(Curve)
Points
(Vertices)
Included
in the
Peak
Corner
Vertices
of the
Peak
Length
of the
Peak
(1/cm)
Maximum
Intensity
of the
Peak (ye)
Left
Boundary
(1/cm)
Right
Boundary
(1/cm)
1 1, 2, 3, 4 1, 4 2.48 36864 1542.18 1544.66
2 4, 5,
6
4, 6 1.66 36029 1544.66 1546.32
3 6, 7, 8 6, 8 1.65 36133 1546.32 1547.97
4 8, 9, 10,
11, 12
8, 12 3.31 36216 1547.97 1551.28
5 12, 13,
14
12, 14 1.66 35719 1551.28 1552.94
6 14, 15,
16
14, 16 1.65 36983 1552.94 1554.59
7 16, 17,
18, 19
16, 19 2.48 36133 1554.59 1557.07
8 19, 20,
21, 22
19, 22 2.48 36236 1557.07 1559.55
9 22, 23,
24, 25
22, 25 2.48 36195 1559.55 1562.03
10 25, 26,
27
25, 27 1.66 35472 1562.03 1563.69
Table 2 – Description of the Peaks n the Raman Signal
from High Pressure Sensor
130
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
where εt is a physical strain tensor defined by the replacement in
the following rr rttr )1( ε+→ , and σt is a physical stress tensor.
General strain-stress relations are
...
2
1
,
++= ηη∑η∑ kj
kj
ijkj
j
iji CCt
...
2
1
,
++= ηη∑η∑ kj
kj
jkj
j
j AAur ,
where CC ijkij , are elastic constants and ur is a vector of all
relative replacements and AA jkj , are internal strain tensors. We
assume that bearing load plane of diamond anvil and bearing load
of the 13C diamond layer to be parallel and to be (100). We have
then the case of strain directed as [100] and thus the strain tensor
η
t
will be written in rather simple way
η
=η
000
000
001
]100[
t
.
Notice that for the case of [110] strain the tensor will be
ηη
ηη
=η
000
0
0
11
11
]110[
t
.
For the case of [111] case the tensor will look like this
ηηη
ηηη
ηηη
=η
144
414
441
]111[
2
1
2
1
2
1
2
1
2
1
2
1
t
.
131
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
2
111211232
2
11111111
2
1
;
2
1
η+η==
η+η=
CCtt
CCt
For [100] strain case the stress tensor
=
3
2
1
]100[
00
00
00
t
t
t
t
t
is
presented by the main components 321 ,, ttt . In our case they are
equal to.
For case of [110] strain case the stress tensor components ]110[t
t
are written in the following way
.42
,)2(2
,)43(
2
1)(
2
11661446
2
11441231121123
2
11661121111121121
η+η=
η+++η=
η+++η+==
CCt
CCCCt
CCCCCtt
For case of [111] strain case the stress tensor components ]111[t
t
are written in the following way
.)2(
,)2(
2
1
)26(
2
1)2(
2
445641166144444654
2
4166144
2
112311211111211321
η+ηη++η===
η++
+η+++η+===
CCCCttt
CC
CCCCCttt
We also plan to use Eulerian approach in order to use the Birch
equation of state and to compare each obtained result in both
theories. Both theories differ in the coordinate systems being fixed
and associated with some apriori chosen inertial coordinate system
132
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
or coordinate system is being inbuilt in the solid and is under
transformation as well as the solid is. We present the Birch’s results
[3] which connects Eulerian strain Eηt tensor and Eulerian stress
tensor Et
t
).1()1)(1det(
];)21(1[
2
1])1(1[
2
1 12
ε+σε+ε+=
η+−=ε+−=η −−
tttttttt
ttttttt
E
E
t
In Nike2D model we use cylindrical system of coordinates and
regular notation is the following for [100] strain case.
32
3
2
1
,
,
,
σ=σ
σ=σ
σ=σ
σ=σ
ϑϑ
rr
zz
where using elastic constants presented in [1] for Lagrangian and
Euler theories we write the following stress/strain dependencies for
stress tensor for the case of [100] strain.
Lagrangian Approach.
2
1132
2
111
400125
;31501081
η−η==
η−η=
tt
t
Eulerian Approach.
2
1132
2
111
415125
;27851081
η−η==
η+η=
tt
t
These relations are shown on Fig. 3.
133
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
Fig.3. Stress/Strain Relations in Lagrange and Euler theories for [100]
strain case
As we can see the Lagrangian approach gives better approximation
to the experimental data. Nike2D simulation model also well match
First Main Stress Component in the stress tensor for Lagrangian
approach. For the case of [110] strain the tensor stress components
are
134
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
Lagrangian Approach.
;64501207 2
1121 η−η== tt
.104404.1158
;710250
2
116
2
113
η−η=
η−η=
t
t
Eulerian Approach.
.31324.1158
;150250
;5.31031207
2
116
2
113
2
1121
η+η=
η+η=
η+η==
t
t
tt
For the case of [111] strain the stress tensor components are.
Lagrangian Approach.
.131051902.579
;259518755.1331
2
4414654
2
4
2
11321
η−ηη−η==
η−η−η===
ttt
ttt
Euleria Approach.
.57117192.579
;5.8599655.1332
2
4414654
2
4
2
11321
η+ηη+η===
η+η+η===
ttt
ttt
High Pressure Sensor Calibration (Present Models). The use of
13C diamond layer as a high pressure sensor and its calibration was
described in [2]. The calibration of this type of sensor was also
investigated by different authors and as was confirmed in [2] a
quadratic fit for a relative shift of a Raman peak with respect to
pressure is a good model. If 0ω−ω=ω∆ is a relative shift of a
Raman peak and P is a pressure then the following quadratic fit
2bPaP ==ω∆ , where a and b are constants is valid. Several
comparable fits are presented in the Table 3 below.
Diamond Equation of State. We consider two equations of state
for diamond : one suggested by Birch [4] , another by Murnaghan
[5]. On Fig. (left) the Birch equation of state is shown, on Fig.
135
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
Table 3 — Different Quadratic Fits for a Relative Shift
of a Raman Peak
# Source Constant a Constant b
1 Eremets 2.258 - 0.0024
2 Akahama et al. 2.179 - 0.0018
3 Sun et al. 2.062 - 0.0014
4 Wei et al. 2.418 - 0.0038
5 Our Nike2D Model 2.423 - 0.0034
(right) the Murnaghan equation of state is shown, on Fig. our
Nike2D simulation model results are shown. The Nike2D model
simulation results are very close to the Birch model. The parameter
used in Nnike2d model is the ratio (V0/V) -1 , we use the same
parameter for the Birch and Murnaghan models for easy comparison.
If B is a bulk modulus, constant==′
dP
dBB , then for diamond we
have the following Murnaghan diamond equation of state.
]1)[(62.158 9.20 −=
V
VP ,
0V is the volume at ambient pressure and V is a current volume.
Birch diamond equation of state
−
+
−
= )1(375.0115.658
3/2
0
3/2
0
3/5
0
V
V
V
V
V
VP
In Nike2D the parameter used is the following ratio: 10 −
V
V
.
For the purpose of better comparison we present the Birch and
Murnaghan equations of state for diamond with respect to the same
ratio. Both Birc We notice that much better comparison with Nike2D
model diamond equation of state was made for the Birch transformed
model. Nike2D model is shown on Fig.5. Birch and Murnaghan
transformed functions are shown on Fig.4.
136
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
Fig. 4 . Birch transformed and Murnaghan transformed Diamond
Equation of State
Fig.5. Nike2D Model Diamond Equation of State
Optical à Phonon Behavior with respect to Stress and Strain.
We assume as in [1] that the optical à phonon is completely
described by the phonon-frequency tensor
⎥
⎥
⎥
⎦
⎤
⎢
⎢
⎢
⎣
⎡
ΩΩΩ
ΩΩΩ
ΩΩΩ
=Ω
345
426
561t
.
Phonon-frequency tensor components maybe expressed as
functions of strain
...}
2
1{
,
0 +ηηΩ+ηΩ+δω=Ω ∑∑ kj
kj
ijkj
j
ijii ,
137
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
where }{ iδ=δ
t
is a unit tensor, ijkij ΩΩ , are dimensionless
phonoelastic constants. In the case of [100] strain we have the following
relations for normal mode frequencies of phonon-frequency tensor.
)
2
11(
);
2
11(
2
1112112032
2
111111101
ηΩ+ηΩ+ω=Ω=Ω
ηΩ+ηΩ+ω=Ω
Notice that for the case of small pressure value we can restrict
our case only with [100] strain. With the pressure increased we have
automatically strain appearing in [110] direction and with further
pressure increase in [111] direction. The main reason is that the
diamond unit cell are being deformed from its initial equilibrium
position and those cases will automatically appear due shear stress
and other effects.The resultant strain is some linear combination of
strains in all these three directions mentioned above. All of this will
cause us also to consider these directions as separate and important
ones. For the case of [110] strain we have for phonoelastic tensor
).42(
],)2(21[
],)43(
2
1
)(1[
2
1166114406
2
114412311211203
2
1166112111
11211021
ηΩ+ηΩω=Ω
ηΩ+Ω+Ω+ηΩ+ω=Ω
ηΩ+Ω+Ω+
+ηΩ+Ω+ω=Ω=Ω
The normal modes for the case of [110] strain are
.;; 36161 ΩΩ−ΩΩ+Ω For Lagrangian approach we have the
following normal modes for [110] strain
.5.9607806.19541281
;144.3105414.1201281
;768.2469978.55561281
2
113
2
1161
2
1161
η+η−=Ω
η+η−=Ω−Ω
η+η−=Ω+Ω
138
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
Dependence of strain is shown on Fig.6. Normal modes for
[110] strain for Eulerian approach
.26.69948.19541281
;4.5268.3811281
;242736.52951281
2
113
2
1161
2
1161
η+η−=Ω
η+η−=Ω−Ω
η−η−=Ω+Ω
Fig. 6. Normal Modes for Case of [110] Strain (Lagrangian Approach).
Fig. 7. Normal Modes for Case of [110] Strain (Eulerian Approach).
On Fig.7 normal modes vs. strain for the case of [110] strain for
Eulerian approach is shown.
For the case of [111] strain we have the following components
of the phonoelastic tensor.
139
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
).)2([
],)2(
2
1)26(
2
1
)2(1[
2
4456411661444440654
2
4166144
2
1123112111
112110321
ηΩ+ηηΩ+Ω+ηΩω=Ω=Ω=Ω
ηΩ+Ω+ηΩ+Ω+Ω+
+ηΩ+Ω+ω=Ω=Ω=Ω
The normal modes for the case of [111] strain are
4141 ,2 Ω−ΩΩ+Ω , the last is double degenerate. The normal modes
for the case of [111] strain for Lagrangian approach are
.4.16786.7686.1224
885.638161281
;9.33552.15372.2449
885.6381612812
2
4414
2
1141
2
4414
2
1141
η+ηη−η+
+η+η−=Ω−Ω
η−ηη+η−
−η+η−=Ω+Ω
The normal modes for [111] strain for Eulerian approach are
presented in the following way
.7.92870075.1228
6.710738161281
,1.8653140142457
6.7107381612812
2
4414
2
1141
2
4414
2
1141
η−ηη+η+
+η−η−=Ω−Ω
η−ηη−η−
−η−η−=Ω+Ω
Our investigation shows that the relative shift of a Raman peak
follows the following Hanfland et al [ ] equation. And it is the best
fit for it. We have calculated the parameters of Hanfland model
fitting experimental data. The model now is
−
ω
ω−
−
ω
ω
ω
ω= }1{2545.01195.859
3/2
0
3/2
0
3/5
0
P .
140
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
Notice that the parameters of the Hanfland model which fit the
experimental data are a = 573.3 GPa, b = 0.2545 (dimensionless).
In experimental data we used 0ω =1281 1/cm. The dependence between
P and ω is shown on Fig. 8. Hanfland dependence is presented in
the form of direct and inverse functions. On Fig.9 is shown the same
type of dependence we obtained by simulation this problem using the
Nike 2D model in the form of direct and inverse functions.
Fig. 8. Hanfland Pressure / Wave Number Model (direct and inverse
representation)
Fig. 9. Nike2d Model connecting pressure and wave number
For alternative model we used Nielsen model [1] which for [100] strain
case normal mode frequencies for phonon-frequency tensor will be.
Lagrangian approach.
1281
;75.96056.9731281
;45.18571281
0
2
1132
11
=ω
η+η−=Ω=Ω
η−=Ω
141
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
Eulerian approach.
2
1132
2
111
65.83256.9731281
;384345.18571281
η−η−=Ω=Ω
η−η−=Ω
12810 =ω . Both Lagrangian and Euler approaches for Nielsen
model are shown on Fig.10.
Maximum Shear Stress. We investigated the behavior of maximum
shear stress for [100] strain case in order to find points where the
anvil may fail. If maxτ is a maximum shear stress, then
2
11211112111
21
max )(
4
1)(
2
1
2
η−+−η=
−
=τ CCCCtt
Fig. 10. Normal Mode Frequencies for Nielsen model
(Lagrangian and Euler representation)
142
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
Lagrangian approach.
2
max 13755.461 η−η=τ .
Eulerian approach. 2
max 16005.461 η+η=τ .
Both functions are presented on Fig.11. The point of interest for
us will be the strain value for which the maximum shear stress
reaches value of about 100GPa. Behavior of maximum shear stress
is more realistic in Lagrangian approach.
Investigation of R1 ratio. We introduce the variable R1,
z
rR
σ
σ
=1
This ratio is rather important in diamond anvil compression
problem. Our goal to connect values of R1 with the [100] strain. We
have for ratio R1
η+
η+
=
η+η
η+η
==
11111
11212
2
1111111
2
1112112
1
2
2
2
2
1
2
1
1
CC
CC
CC
CC
t
tR
Fig.11. Relation of Maximum Shear Stress vs [100] Strain
(Lagrangian and Euler approach).
As the result we obtain.
143
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
Lagrangian approach.
1
1
63002100
8002541
η−
η−
=R .
Eulerian approach.
1
1
55702100
8302541
η+
η−
=R .
These ratios for Lagrangian and Eulerian approaches are presented
on Fig.12. Analysis shows full advantage of Euler theory for R1 ratio.
Fig.12. Ratio R1 for Lagrangian and Euler approaches
Description of a Raman Peak Shift of Γ Optical Phonon using
Coordinate Position. The advantage of Nielsen model presented before
for the case of [100] strain based upon the use of strain tensor component.
We connect normal mode frequencies of phonon-frequency tensor with
the measuring point location in a strained diamond using
1
0
1 −=η
x
x
.
Lagrangian approach.
)/1(1281 ];51.226.275.0[
];33.133.2[
0
0
2
0
032
0
01
cm
x
x
x
x
x
x
=ω+⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
−⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
ω=Ω=Ω
−ω=Ω
1
0
1 −=η
x
x
144
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
Eulerian approach.
];11.154.065.0[
];67.067.43[
0
2
0
032
0
2
0
01
+⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
+⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
−ω=Ω=Ω
−⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
+⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
−ω=Ω
x
x
x
x
x
x
x
x
=ω0 1281 1/cm. These dependencies are presented on Fig. 13.
Fig. 13. Normal Mode Frequencies of Optical Γ Phonon in a [100]
Strained Diamond
145
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
Notice that both models explain split of triplet of optical phonon
in unstrained diamond (Hanfland model does not show that) in a
singlet and doublet (First Mode Frequency explains a singlet , the
Second and the Third Mode Frequency represent the doublet ).
Also we can see that these normal modes behavior is relatively
close to experimental data (Eulerian approach).
Description of Pressure with respect to Coordinate Position. For
the case of [100] strain we don’t have any internal parameter to be
calculated for describing the internal stress/strain relations. For
unstrained diamond for [100] strain case the loading axis is x axis
and let 0x be the initial position. Basically in this case we are
talking about the tip of 13C diamond layer, physically it corresponds
to the gasket/diamond layer interface. Notice that for the case of
0xx = all stress, strain, pressure values will be equal to zero. By
changing the position of x we will obtain stress and strain values not
equal zero and for negative values of strain (compression in negative
x axis direction) we will connect these values with the stress tensor
components. Notice that the same type of curve will be obtained
if the pressure on gasket/diamond anvil is not equal zero and lets
it will be some value of pressure 0P , then along the loading axis
with respect to loading (axial) coordinate this value will be added
to each pressure component. Thus the study of pressure vs coordinate
position in a strained diamond is essential. For the strain in [100]
direction we have the following relation
11
000
0
0
1 −=−=−=∆=η
x
x
l
l
l
ll
l
l
.
Using relation between strain and physical strain tensors can also
easily can connect them in the following way:
11 211 η++−=ε . We will make the following mathematical
assumptions (for the case of [100] strain). 3
2 31 ttP += , where
2
111211232
2
11111111 ;
2
1 η+η==η+η= CCttCCt . Thus
146
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
2
1
111112
1
1112 )
63
()
33
2( η++η+= CCCCP . In the form of pressure/
coordinate x representation
)].2(2)2[(
6
1)](2
)[(
3
1)2(
6
1
121121111111212
11111
0
112111
2
0
CCCCCC
CC
x
xCC
x
xP
−+−+−+
+−
++
=
Using elastic constants for Lagrangian and Eulerian theories we
obtain the following functions.
Lagrangian approach.
0
0
2
0
],33.1)(33.2)[(67.1316 xx
x
x
x
xP ≤+−−= .
Eulerian approach.
0
0
2
0
],33.0)(33.1)[(67.651 xx
x
x
x
xP ≤+−= .
These pressure/loading coordinate relations for Lagrangian and
Eulerian approaches are presented on Fig.15. The curve for
Lagrangian approach gives a good agreement with our Nike2d
computer simulation model.
Change of Total Energy with respect to Strain. We investigate the
change of total energy of a diamond using Nielsen approach for
[100] strain case. We will have the following function related to
strain in [100] direction.
4
11111
3
1111
2
111
0 24
1
6
1
2
1 η+η+η=∆ CCC
V
Etotal
.
Using values of elastic constants we obtain
147
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
Fig.15. Total Diamond Crystal Energy Change as Function of Strain
for [100] case (Lagrangian and Euler Approaches)
Fig.14. Pressure vs ratio
0x
x
(Lagrangian and Eulerian approach)
Lagrangian approach. 4
1
3
1
2
1
0
67.1811050525 η+η−η=
Δ
V
Etotal .
Eulerian approach. 4
1
3
1
2
1
0
17.67933.928525 η+η+η=
Δ
V
Etotal .
Both functions are on Fig. 15.
148
Åêîëîã³÷íà áåçïåêà òà ïðèðîäîêîðèñòóâàííÿ
Notice that in case of Lagrange approach the energy change is
about four times faster than in case of Eulerian approach. On our
opinion Lagrangian approach is more preferable.
Conclusions
1. We proved that Hanfland et al model for the relative shift of
a Raman peak is a much better fit the the well known and well
accepted quadratic fit. The Hanfland model was also confirmed by
our simulations on Nike2D computer model.
2. Our Nike2d simulation model has shown the full advantage
of Birch equation of state for diamond.
We confirmed by investigation and by computer simulation that
under the external pressure the splitting occurs (into singlet and
doublet) of Γ 1.optical phonon which was originally triply
degenerate in unstrained diamond crystal. Our main results were
confirmed in our Nike2D computer simulation model.
2. The peaks 1, 7, 8, 9 (Table 2) are produced by first normal
mode in [100] strained compressed sensor cells. Peaks 2, 3, 5, 6,
10 are produced by first normal mode in [110] strained compressed
sensor cells. Peak 4 is produced by first normal mode in [111]
strained compressed sensor cell.
5. We considered applications of our results in ecological safety
and use of natural resources.
Discussion
1. We study the behavior of Γ phonons along the loading axis
of diamond anvils and high pressure sensor. While being compressed
the strained diamond anvils and high pressure sensor cells along the
initial loading axis will be located in arbitrary order with respect to
the direction of this axis. For a randomly chosen diamond cell
along the Γ phonon axis the direction of a cell axis
.1coscoscos );cos,cos,(cos 222 =γ+β+αγβα=nv
Then we have the following
149
ÏðåðîìàíòèçìÐîçä³ë 3. ²íòåëåêòóàëüí³ ðåñóðñè. Íàóêîâî-òåõíîëîã³÷íà áåçïåêà
( ) ( ) .
1
1
1
cos
0
1
1
coscos
0
0
1
coscos
1
0
0
cos
0
1
0
cos
0
0
1
cos
cos
cos
cos
γ+
γ−β+
β−α
=
γ+
β+
α=
γ
β
α
The last shows that arbitrary chosen strained direction maybe
represented as the linear combination of [100], [110], and [111]
strained directions.
2. We assume that along the Γ phonon line the diamond cells
are arbitrary oriented in all of these three directions [100], [110],
and [111] in the proportion .1;:: =++ cbacba
References
1. O.H.Nielsen, Phys.Rev. B, 34, 5808 (1986).
2. Wei Qiu, P.A.Baker, N.Velisavljevic, Y.K.Vohra, S.T.Weir,
J. Appl.Phys. 99,1 (2006).
3. F.Birch, Phys.Rev.71, 809 (1947).
4. F.Birch, J.Geophys.Res. 57, 227 (1952).
5. F.D. Murnaghan, Proc. Natl. Acad. Sci. USA 50, 697 (1944).
6. M.Hanfland, K.Syassen, S.Fahy, S.G.Louie, and M.L.Cohen,
Phys.Rev. B 31, 6896 (1985).
Îòðèìàíî: 17.04.2009 ð.
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