high pressure study of bromine shimizu lab m1 hayashi yuma
TRANSCRIPT
High Pressure study of Bromine
Shimizu LabM1 Hayashi Yuma
Contents• Introduction Iodine• Bromine• Summary• Next plan
Introduction
http://www.cqst.osaka-u.ac.jp
room –temperature superconductor?
High-Pressure Effect
MoleculeInsulator
pressurization pressurization monatomic metal
molecular dissociation ( 分子解離 )
( 単原子金属 )
Applying pressure means…
Electronic states change.
The atomic distance becomes closer.・ Structural transition・ Insulator-Metal transition
introduction
Structural phase transition of iodine
• molecular• insulator
I phase
Ambient pressure
・ atomic ・ metal
Y. Fujii, K. Hase, N. Hamaya, Y. Ohishi, A. Onodera, O. Shimomura, and K. Takemura, Phys. Rev. Lett. 58, 796 (1987).
B. Albert, K. Schmit, Z. Anorg. Allg. Chem. 627, 809 (2001).
Molecular dissociation @21GPa
High pressure
introduction
body-centered-orthorhombic
body-centered-tetragonal
face-centered-cubic
Electrical property of Iodine in high pressure
N. Sakai, K. Takemura and K. Tsuji, J. Phys.Soc. Jpn. 51, 1811 (1982).
0 10 20 30 40 500.0
0.5
1.0
1.5
2.0
R/R
50K
T (K)
12 GPa
13 GPa
14 GPa
16 GPa
18 GPa
iodine
The temperature dependence of electrical resistance of iodine becomes positive at 14-16 GPa, indicating insulator to metal transition
introduction
Superconductivity of iodine
K. Shimizu et al., J. Phys. Soc. Jpn., 61, 3853 (1992).
Iodine becomes superconductor in phase at about 1.2 K.Ⅱ
introduction
Hall Effect of Iodine
・ The carrier of iodine is ‘hole’.
[top view]
I- I+
V- V+
V0
B
introduction
T. Yamauchi et al., J. Phys. Soc. Jpn., 63, 3207-3209 (1994).
RH ＝
（ n ： carrier density ）
Tc∝θDexp[-1/N(0)V ]
introduction
Phase diagram of iodine
Crystal structure Molecular phase ( )Ⅰ
Monatomic phase
0
Pressure [GPa]
21
Insulator metal
Superconductor
16
R.T.
Electrical
characteristic
43 55
( )Ⅱ ( )Ⅲ ( )Ⅳ
Molecular dissociation
introduction
・ The carrier of iodine is ‘hole’.
・ Iodine becomes superconductor in phase at about 1.2 K.Ⅱ
Ⅴ phase between and phase Ⅰ Ⅱat 24-25 GPa
K. Takemura et al., Nature 423, 971 (2003).
・ incommensurate structure
・ metal
( )Ⅴ
Crystal structure Molecular phase ( )Ⅰ
Monoatomic phaseR.T.
( )Ⅱ ( )Ⅲ ( )Ⅳ
introduction
Introduction
http://www.cqst.osaka-u.ac.jp
room –temperature superconductor?
High-Pressure Effect
MoleculeInsulator
pressurization pressurization monatomic metal
molecular dissociation ( 分子解離 )
( 単原子金属 )
Applying pressure means…
Electronic states change.
The atomic distance becomes closer.・ Structural transition・ Insulator-Metal transition
introduction
Structural phase transition of iodine
• molecular• insulator
I phase
Ambient pressure
・ atomic ・ metal
Y. Fujii, K. Hase, N. Hamaya, Y. Ohishi, A. Onodera, O. Shimomura, and K. Takemura, Phys. Rev. Lett. 58, 796 (1987).
B. Albert, K. Schmit, Z. Anorg. Allg. Chem. 627, 809 (2001).
Molecular dissociation @21GPa
High pressure
introduction
body-centered-orthorhombic
body-centered-tetragonal
face-centered-cubic
Electrical property of Iodine in high pressure
N. Sakai, K. Takemura and K. Tsuji, J. Phys.Soc. Jpn. 51, 1811 (1982).
0 10 20 30 40 500.0
0.5
1.0
1.5
2.0
R/R
50K
T (K)
12 GPa
13 GPa
14 GPa
16 GPa
18 GPa
iodine
The temperature dependence of electrical resistance of iodine becomes positive at 14-16 GPa, indicating insulator to metal transition
introduction
Superconductivity of iodine
K. Shimizu et al., J. Phys. Soc. Jpn., 61, 3853 (1992).
Iodine becomes superconductor in phase at about 1.2 K.Ⅱ
introduction
Hall Effect of Iodine
・ The carrier of iodine is ‘hole’.
[top view]
I- I+
V- V+
V0
B
introduction
T. Yamauchi et al., J. Phys. Soc. Jpn., 63, 3207-3209 (1994).
RH ＝
（ n ： carrier density ）
Tc∝θDexp[-1/N(0)V ]
introduction
Phase diagram of iodine
Crystal structure Molecular phase ( )Ⅰ
Monatomic phase
0
Pressure [GPa]
21
Insulator metal
Superconductor
16
R.T.
Electrical
characteristic
43 55
( )Ⅱ ( )Ⅲ ( )Ⅳ
Molecular dissociation
introduction
・ The carrier of iodine is ‘hole’.
・ Iodine becomes superconductor in phase at about 1.2 K.Ⅱ
Ⅴ phase between and phase Ⅰ Ⅱat 24-25 GPa
K. Takemura et al., Nature 423, 971 (2003).
・ incommensurate structure
・ metal
( )Ⅴ
Crystal structure Molecular phase ( )Ⅰ
Monoatomic phaseR.T.
( )Ⅱ ( )Ⅲ ( )Ⅳ
introduction
Structural phase transition of bromineMolecular dissociation near 80 GPa
Y. Fujii et al.,Phys. Rev. Lett. 63, 536(1989)
Electrical property of bromine
K Amaya et al 1998 J. Phys.: Condens. Matter 10 11179
Above 90GPa, small drops in electrical resistance are observed, which show the onset of superconductivity.
Summary
• Bromine has molecular dissociation near 80GPa.
• Under high pressure, bromine has the same structure changes as iodine.
• At pressure higher than 90GPa, small drops in electrical resistance are observed, which show the onset of superconductivity.
Next plan
I will perform electrical resistance measurement of solid bromine at high pressure again,
Because pressure measurements above 140 GPa may be incorrect.
How to estimate pressure
Ruby produces fluorescence when irradiated by laser. The wavelength of the peak changes with pressure.
For P < 100 GPa : Ruby Fluorescence （ルビー蛍光法）
For P > 100 GPa : Raman Spectroscopy ( ラマン分光法）
P = 66.9 - 0.5281ν + 3.585×10-4 ν2
Irradiate diamond with laser. On applying pressure, the vibration of C-C bond in diamond changes, the
wavelength of scattered light becomes small.