4th ilias-gw annual meeting j.p. zendri tuebingen 8-9 october 2007 materials for dual: losses at low...

4th ILIAS-GW Annual Meeting J.P. Zendri Tuebingen 8-9 October 2007

Materials for Dual:

Losses at low Temperature on Si and SiC


Materials under investigation

Samples shape

•Silicon single crystal and bonded

•Silicon Carbide

•Cantilever beams

•DisksExperimental set-up (2-300 K)

Heater

Shacker

Capacitive and optical readout

Thermometer

DUAL requirement •T<10-8


Samples suspension

Recently: glued suspension

•Less invasive on the sample

• One face of the sample is free

Sapphire balls

SS spring

Sample

Glued Sapphire ball


Silicon

Sample: mono crystalline silicon (n type P doped) disks 4 inch in diameter 0.5 mm in thickness

0 50 100 150 200 250 300

1E-8

1E-7

1E-6

1E-5

1E-4

Loss

Ang

le

Temperature [K]

2512 Hz 1724 Hz 381 Hz

Mode Shape Frequency

381 Hz

1724 Hz

2512 Hz


Dissipation around 125 K

H: thickness change of the

disk center averaged over a

circular area 0.3 mm in diameter

Emode: elastic energy stored

in the mode

•Finite size of the sapphire ball

•Disc thickness change

Real nodal point suspension

The region around 125 K is dominated by clamping losses

H2/Emode proportional of the fraction of the elastic energy that couples to the holder

FEM calculation:

Opt. readout

Cap. readout


Dissipation mechanism T≠125K

Below 50 K

•Not evidence of clamping losses as at 125K

•Squeezed gas damping losses order of 10-8

• Surface losses?

0 50 100 150 200 250 3001E-10

1E-9

1E-8

1E-7

1E-6

1E-5

1E-4

Loss

ang

le

Temperature [K]

Exper K span-max K span-min

Coupled field thermoelastic FEM Analysis


Glued suspension

2 10 100 3001E-8

1E-7

1E-6

1E-5

1E-4

Mode 1737 Hz

Loss

Ang

le

Temperature [K]

Suspension glued Suspension with spring

Advantages

•Increased thermal conductivity

•Less invasive

•Pressure less

•One face is free (for instance for coating layers)


First Bonded Si run

Direct bonding

•Pressure 4 bar

•Temperature 500 C

•Post processing annealing 2 hours at 1100 C

3 monocristalline Si disks bonded together using ‘direct bonding’

Single disc thickness 0.3 mm, diameter 4 inch

Glued suspension & capacitive readout

First Measurements (run in progress)

Bonded disk

0 10 20 30 40 50 60 70 80 90

1E-6

Loss

Ang

le

Temperature [K]

695.9 Hz 4840 Hz 6825.4 Hz


bonded Si: preliminary results

h=0.9 mm

d=0.15 mm

)()()( bondtot

bondBulkMeas E

E

ASSUMING

)()( bondtot

bondBulk E

E

nmt 80

1.

2.

53

2 10612

6

t

tE

E

tot

bond dh3

3.

BulkBond YY

(Dual goal order of 10-3)?

0 10 20 30 40 50 60 70 80 90

0,01

0,1

Bond

ing

loss

Ang

le

Temperature [K]

695.9 Hz 4840 Hz 6825.4 Hz


Silicon carbide Considered Samples

Typology Phase PolyType Sample Shape

Supplier

Sintered 1 AlphaUnknow

nBeams

Bettini (I)Disks

Sintered 2 Beta Unknown

Disks Bridgeston (J)

Infiltrated C/SiC

BeamsCesic (D)

Disks

Single crystal Beta4H Disk

Cree (USA)6H Disk




Supplier


nBeams

Bettini (I)Disks



Infiltrated C/SiC

BeamsCesic (D)

Disks


Cree (USA)6H Disk

Already reported




Supplier


nBeams

Bettini (I)Disks



Infiltrated C/SiC

BeamsCesic (D)

Disks


Cree (USA)6H Disk

Already reported

Report on this meeting




Supplier


nBeams

Bettini (I)Disks



Infiltrated C/SiC

BeamsCesic (D)

Disks


Cree (USA)6H Disk

Already reported

Report on this meetingStill not measured


C/SiC disks measurements

•Samples: disks 3 inch in diameter 1,2,3 mm in thickness

•Two different carbon matrix

•Nodal point suspension

•Capacitive readout

•Two normal modes investigated


C/SiC disks measurements

2 10 100 3002E-6

1E-5

1E-4

Loss

Ang

le

Temperature [K]

Disck1mm Disk 2mm 2067 Hz 3470 Hz 2070 Hz 3437 Hz 4747 Hz 7947 Hz 4750 Hz 7950 Hz

1. Not evidence of a frequency dependence → Thermoelastic dissipation not dominant

2. Not evidence of a thickness dependence → Surface dissipation not dominant


C/SiC carbon matrix size effect

2 10 100 3002E-6

1E-5

1E-4Disk Thickness 1mm Second Doublet

Loss

Ang

le

Temperature [K]

DiskA 4747 Hz DiskA 4750 Hz DiskB 4714 Hz DiskB 4715 Hz

1 10 100 5002E-6

1E-5

9E-5Disk Thickness 1mm First Doublet

Loss

Ang

le

Temperature [K]


2 10 100 3002E-6

1E-5

8E-5Disk Thickness 2mm First Doublet

Loss

Ang

le

Temperature [K]


Weak

dependence

2 10 100 3002E-6

1E-5

1E-4Disk Thickness 2mm Second Doublet

Loss

Ang

le

Temperature [K]


Disk A:

bigger size of the C-matrix

Disk B:

Smaller size of the C-matrix


Single crystal SiC

SAMPLES

•Disks 2 inch in diameter

•About 0.3 mm in thickness

•Two different polytypes

4H and 6H

Experimental set-up

•Nodal suspension (glued)

•Capacitive readout (comb cap)

4H SiC6H SiC

Capacitive readout


Single crystal SiC: preliminary measurements

Measurements in progress

0 20 40 60 80 100

1E-6

1E-5

3E-5

loss

Ang

le

Temperature [K]

4H SiC 4980 Hz 6H SiC 5120 Hz C/SiC 4747 Hz


C/SiC disk

2 10 100 3002E-6

1E-5

1E-4

Loss

Ang

le

Temperature [K]

Disck1mm Disk 2mm 2067 Hz 3470 Hz 2070 Hz 3437 Hz 4747 Hz 7947 Hz 4750 Hz 7950 Hz

2 10 100-0,0004

-0,0002

0,0000

0,0002

Disk1mm 2067 Hz Disk2mm 3470 Hz Disk1mm 2070 Hz Disk2mm 3473 Hz Disk1mm 4747 Hz Disk2mm 7947 Hz Disk1mm 4750 Hz Disk2mm 7950 Hz

Temperature [K]

Not exluded quantum tunneling of two level systems

Hope that at ultralow temperature scales as T-3

Weak temperature dependence

Logaritmic dependence

Loss Angle Relative frequency shift


C/SiC ultrlow temperature measurement

The samples has been assembled past Friday in a DR of the Trento Univ.

Experimental set-up

SiC Disk for

Q measurements

Shacker

Capactive readout

SiC Disk with thermometer

4th ILIAS-GW annual meeting

Summary

•Developed an experimental apparatus for measuring mechanical losses down to 10-8 at cryogenic temperature

•The first cryogenic measurements on Si bonded Disc is in progress

•Regardless the fabrication process the low temperature loss angle of the Silicon Carbide never go down to 10-6 . Ultracryogenic can help?

Next year program•Extend the measurements at ultracryogenic temperatures

•Systematic measurements on Si bonding losses

•Measure the thermal conductivity of bonding

•Complete the measurements on all the typology of SiC (beta phase)

•Measurement in collaboration with other Ilias groups


Facility for the Q-factor measurement

IVC P=10-6

mbar

Sample (disk)

Suspension and thermal link

Holder (low thermal cond.)

Samples prop Actively thermal. (2-300K )

Cryogenic Liquid

LHe4 or LN2

4th ilias-gw annual meeting j.p. zendri tuebingen 8-9 october 2007 materials for dual: losses at low...

Documents

zendri tuebingen

silicon sample

surface losses

c3 monocristalline si

elastic energy

glued suspensionless

dual goal order

invasive pressure lessone