Crystal Growth under High Pressure
• In previous lectures: – Pressure units, pressure mediums – Measurements in high pressure cells
• Interest of high pressure for crystal growth
– – –
• How does our high pressure furnace work ? – Cubic high pressure set up – A few tricks to get a sense of high pressure experiments
pressure can modify the stability of some crystal structures which remain stable at ambient pressure due to the transformation barriers
Interest of high pressure for crystal growth
What does it mean ?
pressure can modify the stability of some crystal structures which remain stable at ambient pressure due to the transformation barriers
Interest of high pressure for crystal growth
Examples of metastable materials ?
Metastable state
pressure can modify the stability of some crystal structures which remain stable at ambient pressure due to the transformation barriers Famous example of Diamond
Metastable state
Interest of high pressure for crystal growth
pressure can modify the stability of some crystal structures which remain stable at ambient pressure due to the transformation barriers Steel is also metastable
Martensite is formed in carbon steels by the rapid cooling (quenching) of austenite at such a high rate that carbon atoms do not have time to diffuse out of the crystal structure in large enough quantities to form cementite (Fe3C)
Interest of high pressure for crystal growth
Examples of materials grown under high pressure in the last 6 months
Interest of high pressure for crystal growth pressure can modify the stability of some crystal structures which remain stable at ambient pressure due to the transformation barriers
Diamond Li-Si phases c-BN BCN
In2NiMnO6
Sr2Can-1CunOy
CxSr2Ca2Cu3Oz
ThB4O8
UB4O8
BaIrO3
BaOsO3
Fe8B15O28(OH)8 ScRhO3
InRhO3 U2[BO4][PO4] Sr1-yBayRuO3
Bi4O4S3 Mo3S4
Sr3V5S11
FeS2
K2PtH6
Rb2PtH6
Cs2PtH6
Mg3CuHx
IrH3
Li2Ca3[N2]3
S in alpha-HfNBr IrNx
SrCu3Fe4O12
CaCu3V4O12
CaMn3V4O12
LaB2O4F CeB2O4F Mn2FeNbO6
Mn2FeTaO6
NaCr2O4
Sr3Co2O6
BiCu3Mn4-xFexO12
CdRh2O4
[Sr2O2]qCoO2
AgInxSb1-xTe2
B Mg2C Ce7Au13+xGe10-x
Ag3.4In3.7Sb76.4Te16.5
materials leading to publications between July 2013 and December 2013 with “high pressure synthesis” Source: Web Of Science
Crystal Growth under High Pressure
• In previous lectures: – Pressure units, pressure mediums
– Measurements in high pressure cells
• Interest of high pressure for crystal growth – pressure can modify the stability of some crystal structures which
remain stable at ambient pressure due to the transformation barriers
– pressure can increase the solid solubility
• How does our high pressure furnace work ? – Cubic high pressure set up
– A few tricks to get a sense of high pressure experiments
1000
800
600
400
200
0
T (
ºC)
20151050
at. % SiAl
0 GPa
1.6
577 ºC
660 ºC
11.3
pressure can increase the solid solubility
H. Mii et al. Japanese Journal of Applied Physics 15 777 (1976)
Interest of high pressure for crystal growth
How much Si can you substitute into Al ? How ?
1000
800
600
400
200
0
T (
ºC)
20151050
at. % SiAl
0 GPa 2.8 GPa
1.6
577 ºC
660 ºC
11.3
10
660 ºC
840 ºC
pressure can increase the solid solubility
H. Mii et al. Japanese Journal of Applied Physics 15 777 (1976)
Interest of high pressure for crystal growth
pressure can increase the solid solubility
H. Mii et al. Japanese Journal of Applied Physics 15 777 (1976)
Interest of high pressure for crystal growth
Why is it interesting for us ?
1000
800
600
400
200
0
T (
ºC)
20151050
at. % SiAl
0 GPa 2.8 GPa 5.4 GPa
1.6
577 ºC
660 ºC
11.3
10
660 ºC
840 ºC
970 ºC
pressure can increase the solid solubility
V. V. Brazhkin et al. J. Phys.: Condens. Matter 5 5933 (1993)
See also N. E. Sluchanko et al. Phys. Rev. B 51 1122 (1995)
Interest of high pressure for crystal growth
H. Mii et al. Japanese Journal of Applied Physics 15 777 (1976)
1000
800
600
400
200
0
T (
ºC)
20151050
at. % SiAl
0 GPa 2.8 GPa 5.4 GPa
1.6
577 ºC
660 ºC
11.3
10
660 ºC
840 ºC
970 ºC
pressure can increase the solid solubility
Ca1-xPrxFe2As2
Try to get higher Pr content into Ca1-xPrxFe2As2
Interest of high pressure for crystal growth
pressure can increase the solid solubility
Pr 25%
Pr 30%
Ca1-xPrxFe2As2
Try to get higher Pr content into Ca1-xPrxFe2As2
Interest of high pressure for crystal growth
Unfortunately, did not induce superconductivity
Crystal Growth under High Pressure
• In previous lectures: – Pressure units, pressure mediums – Measurements in high pressure cells
• Interest of high pressure for crystal growth
– pressure can modify the stability of some crystal structures which remain stable at ambient pressure due to the transformation barriers
– pressure can increase the solid solubility – pressure can increase the liquidus temperature and the boiling
temperature
• How does our high pressure furnace work ?
– Cubic high pressure set up – A few tricks to get a sense of high pressure experiments
pressure can increase the liquidus temperature and the boiling temperature
Interest of high pressure for crystal growth
What are the 3 regions on the phase diagram ?
pressure can increase the liquidus temperature and the boiling temperature
Interest of high pressure for crystal growth
water/ triethylene glycol (TEG) B. Bender et al. Braz. J. Chem. Eng. 30 75 (2013)
pressure can increase the liquidus temperature and the boiling temperature
Interest of high pressure for crystal growth
G. Balducci et al. J. Phys. Chem. Solids 66 292 (2005)
water/ triethylene glycol (TEG) B. Bender et al. Braz. J. Chem. Eng. 30 75 (2013)
pressure can increase the liquidus temperature and the boiling temperature
Interest of high pressure for crystal growth
G. Balducci et al. J. Phys. Chem. Solids 66 292 (2005) V. Z. Turkevich et al. High Pressure Res. 29 87 (2009)
How would you grow MgB2 ?
pressure can increase the liquidus temperature and the boiling temperature
Interest of high pressure for crystal growth
V. Z. Turkevich et al. High Pressure Res. 29 87 (2009)
10
8
6
4
2
0
(
m)
403020100
T (K)
MgB2 single crystal
Crystal Growth under High Pressure
• In previous lectures: – Pressure units, pressure mediums – Measurements in high pressure cells
• Interest of high pressure for crystal growth
– pressure can modify the stability of some crystal structures which remain stable at ambient pressure due to the transformation barriers
– pressure can increase the solid solubility – pressure can increase the liquidus temperature and the boiling
temperature
• How does our high pressure furnace work ?
– Cubic high pressure set up – A few tricks to get a sense of high pressure experiments
max pressure : 3.3 GPa max temperature : 1800 C
Our high pressure furnace: cubic anvils
The press and the anvils give us the high pressure, but what do I need to make a furnace?
Pyrophyllite: Al2Si4O10(OH)2
max pressure : 3.3 GPa max temperature : 1800 C
Our high pressure furnace: crucible
Although pyrophyllite is very hard, it flows like a soft chewing gum at 3 GPa.
max pressure : 3.3 GPa max temperature : 1800 C
Our high pressure furnace
Crystal Growth under High Pressure
• In previous lectures: – Pressure units, pressure mediums – Measurements in high pressure cells
• Interest of high pressure for crystal growth
– pressure can modify the stability of some crystal structures which remain stable at ambient pressure due to the transformation barriers
– pressure can increase the solid solubility – pressure can increase the liquidus temperature and the boiling temperature
• How does our high pressure furnace work ?
– Cubic high pressure set up – A few tricks to get a sense of high pressure experiments
• get 3.3 GPa without breaking anything • measure the temperature at 3.3 GPa • get 1700 C in the furnace, not on the anvils
Get 3.3 GPa, without breaking anything Compressive strength of tungsten carbide: 4-5.93 GPa Transverse rupture strength: 1.60-2.85 GPa Carbide is classified technically as a “brittle” material since it exhibits little or no plastic deformation preceding the initiation of a crack and total failure.
Our high pressure furnace: a few tricks
Get 3.3 GPa, without breaking anything
Avoid stick-slip motion of the anvils Use molybdenite powder as a solid lubricant
Compressive strength of tungsten carbide: 4-5.93 GPa Transverse rupture strength: 1.60-2.85 GPa Carbide is classified technically as a “brittle” material since it exhibits little or no plastic deformation preceding the initiation of a crack and total failure.
Our high pressure furnace: a few tricks
Avoid stick-slip motion of the anvils Use molybdenite powder as a solid lubricant Use mylar sheets on the side with PTFE lubricant Keep anvils level
Get 3.3 GPa, without breaking anything Our high pressure furnace: a few tricks
Get the thermocouple at 3.3 GPa Our high pressure furnace: a few tricks
Get the thermocouple into a pyrophyllite cube squeezed to 3.3 GPa from every sides. How would you do that?
Get the thermocouple at 3.3 GPa
Alumina tubing as an insulator near the heater Make a strong thermocouple connection make a bent of the wire to allow deformation
Our high pressure furnace: a few tricks
Get the pyrophyllite at 3.3 GPa at 1700 C
Pre heat the pyrophyllite slowly to avoid exothermic dehydratation
Our high pressure furnace: a few tricks
batch to batch variation