Research Article Love Wave Ultraviolet Photodetector ...downloads.hindawi.com/journals/ijp/2014/270186.pdf · Research Article Love Wave Ultraviolet Photodetector Fabricated on aTiO2

Research ArticleLove Wave Ultraviolet Photodetector Fabricated ona TiO2ST-Cut Quartz Structure

Walter Water1 Yi-Shun Lin2 and Chi-Wei Wen1

1 Department of Electronic Engineering National Formosa University Yunlin 632 Taiwan2 Institute of Electro-Optical and Materials Science National Formosa University Yunlin 632 Taiwan

Correspondence should be addressed to Walter Water wwaternfuedutw

Received 30 May 2014 Accepted 20 June 2014 Published 10 July 2014

Academic Editor Teen-Hang Meen

Copyright copy 2014 Walter Water et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

A TiO2thin film deposited on a 90∘ rotated 42∘451015840 ST-cut quartz substrate was applied to fabricate a Love wave ultraviolet

photodetector TiO2thin films were grown by radio frequency magnetron sputtering The crystalline structure and surface

morphology of TiO2thin filmswere examined using X-ray diffraction scanning electronmicroscope and atomic forcemicroscope

The effect of TiO2thin film thickness on the phase velocity electromechanical coupling coefficient temperature coefficient of

frequency and sensitivity of ultraviolet of devices was investigated TiO2thin film increases the electromechanical coupling

coefficient but decreases the temperature coefficient of frequency for Love wave propagation on the 90∘ rotated 42∘451015840 ST-cutquartz For Love wave ultraviolet photodetector application the maximum insertion loss shift and phase shift are 281 dB and 355degree at the 135-120583m-thick TiO

2film

1 Introduction

Titanium dioxide (TiO2) is a wide gap semiconductor and

has three kinds of crystallography structures named anatasebrookite and rutile Anatase phase has the most photocat-alytic activity due to its larger band gap energy (32 eV)and rutile phase has higher refractive index and compactstructure [1 2] TiO

2was intensively investigated on various

fields due to its strong mechanical and chemical stabilityhigh dielectric constant excellent photoelectric activity anddiverse nanostructures [3ndash5] Ever since Fujishima et aldemonstrated photocatalytic activity of TiO

2[6] it became

themost popularmaterial for photocatalysis applications thatcan be applied to decomposite of a large variety of organic andinorganic compounds into environmentally friendly com-pounds The optical absorption energies for photocatalyticactivity of TiO

2have been modified from the ultraviolet to

the visible and near infrared by doping [7 8] The varioussurface morphologies and nanostructures of TiO

2thin films

were grown to increase the absorption ability for opticaldevices applications [9] TiO

2thin film can be synthesized

using various approaches such as chemical vapor deposition

(CVD) [10] sol-gel process [11] pulsed laser deposition [12]hydrothermal method and magnetron sputtering [13ndash15]

Surface acoustic wave (SAW) devices have been widelyapplied in wireless communication components sensors andactuators [16 17] Love wave is the one type of SAWs whichis a shear horizontal polarized wave that has the highestsensitivity in a liquid environment among all known acousticsensors due to the waveguiding effect [18 19] Love wavespropagate in a layered structure consisting of a substrate anda layer on top of it The layer acts as a guide with the elasticwaves generated in the substrate being coupled to the surfaceguiding layer [18]

Leaky waves of LiTaO3and LiNbO

3and surface skim-

ming bulk waves (SSBW) of ST-cut quartz have beenused as substrates for Love wave devices applications [20ndash22] typically ZnO fused silica (SiO

2) and polymethyl-

methacrylate (PMMA) thin films have been used to constructthe layered structure for the Love wave sensor [18 23 24]SSBW transmitted on ST-cut quartz has higher wave velocitythan other substrates ZnO thin film is an excellent guidinglayer for Love wave devices applications because it is apiezoelectricmaterial and can be deposited as various surface

Hindawi Publishing CorporationInternational Journal of PhotoenergyVolume 2014 Article ID 270186 6 pageshttpdxdoiorg1011552014270186

2 International Journal of Photoenergy

morphologies and nanostructures [25 26] But ZnO filmpresents a poor stability in the acid or alkaline solutionsTiO2thin films and TiO

2nanowires have been applied for

various types of UV photodetectors [10 27] but the reportsof Love wave type were few The requirements of guidinglayer for a Love wave device application are being rigiddense and stable and having low radiation loss AlthoughTiO2is not a piezoelectric material its strong mechanical

and chemical stability excellent photoelectric activity andease of synthesizing the various surface morphologies withnanostructures provide the potential as the guiding andsensing layer for Love wave sensors applications

2 Experimental

The Love wave devices were fabricated on ST-cut (42∘451015840)quartz substrates (12mm times 13mm times 05mm) with a propa-gation direction perpendicular to the crystallographic 119909-axis(90∘ rotated) The input and output interdigital transducers(IDTs) consisted of 30 finger pairs with an electrode widthof 10 120583m and separation of 10 120583m yielding a periodicityof 40 120583m The IDT aperture was 4mm and the center tocenter of separation was 62mm The IDTs were made of200 nm sputtered titanium After the contact electrode ofIDTs with a protection the TiO

2films were deposited by RF

magnetron sputtering using a TiO2target (999) In the film

deposition process sputtering power was 350W sputteringpressure was 133 Pa O

2Ar ratio was 025 distance between

substrate and target was 70mm and the substrate was notheatedThe deposition rates were controlled at approximately170 nmhour Figure 1 presents the structure and pattern ofthe Love wave device

The crystalline structure and orientation of the TiO2

films were examined by X-ray diffraction (XRD) (ShimadzuXRD-6000) The surface morphology of the TiO

2films was

analyzed using field-emission scanning electron microscopy(FESEM) (Hitachi S4800-I) and atomic force microscopytechniques (DI D3100) Frequency response phase of trans-mitted signals wave velocities electromechanical couplingcoefficients UV responses and temperature coefficients offrequency of Love wave devices were measured by thenetwork analyzer (Agilent E5062A) The error bars werecalculated as two devices with the same parameters formeasuring three times respectively

3 Results and Discussion

31 Crystalline Structure and Surface Morphology Figure 2presents the XRD patterns of TiO

2thin films with different

thicknesses deposited on quartz substrates The TiO2thin

film at 135-120583m thickness shows an anatase structure andthe major reflection planes are (101) (004) (112) (200) and(211) respectivelyThe films at 050- and 160-120583m thicknessespresent an amorphous structure Figure 3 shows the SEMimages of TiO

2films with various thicknesses The surface

morphology is transferred greatly due to the filmsrsquo thicknessThe 050-120583m thick TiO

2thin film has a smooth surface and

a small columnar size When thickness reaches 085 and

Output IDTQuartz

Input IDT

TiO2 thin film

(a) Top view

Output IDTQuartz

Input IDTTiO2 thin film

(b) Cross-sectional view

Figure 1 Structure of the Love wave device

20 30 40 50 60

Inte

nsity

(au

)

(101)(004)

(112)(200)

(211)

160120583m

135120583m

085120583m

050120583m

2120579 (∘)

Figure 2 XRD patterns of TiO2thin films with various thicknesses

Table 1 The root mean square values and phase velocities of TiO2thin films deposited on quartz substrate with various thicknesses

Thickness(120583m)

Root mean square value(nm)

Phase velocity(ms)

050 047 4907085 284 4814135 334 4787160 587 4725250 1081 4356

135 120583m the polyhedrons with a sharp shape are grown onthe surface and the columnar size increases obviously Thesurface roughness of films turns into rough with increasingthickness The root mean square values of surface roughnessare presented in Table 1

32 Love Wave Device with TiO2Guiding Layer Figure 4

shows the frequency response and phase of transmitted signal(S21) for device with a 16-120583m thick TiO

2film The phase

velocity of a blank ST-cut (42∘451015840) quartz for X-propagationis 5060ms the phase velocity decreases with increasingthickness of TiO

2thin film and approaches 4356ms for

International Journal of Photoenergy 3

(a) Thickness of 050 120583m

(b) Thickness of 085 120583m

(c) Thickness of 135 120583m

(d) Thickness of 160 120583m

Figure 3 SEM images of TiO2thin films with various thicknesses

4 International Journal of PhotoenergyIn

sert

ion

loss

(dB)

Frequency (MHz)

minus4000

minus4500

minus5000

minus5500

minus6000

minus6500

minus7000

minus7500

minus8000

minus8500

minus9000

118116979MHz minus53346dB

Start 93117MHz Stop 143117MHz

(a) Frequency response of transmitted signal

25000

000

15000

10000

5000

20000

Phas

e (de

g)

Frequency (MHz)

minus5000

minus10000

minus15000

minus20000

minus25000

118126979MHz minus39519m∘


(b) Phase of transmitted signal

Figure 4 Frequency response and phase of transmitted signal (S21) of 16-120583m thick TiO

2film

00 05 10 15 20 25 3000

01

02

03

04

05

Thickness (120583m)

K2

()

Figure 5 Electromechanical coupling coefficients of devices withdifferent thicknesses of TiO

2thin films

the 25-120583m thick TiO2film deposited The phase velocities

versus films thicknesses are shown in Table 1The electromechanical coupling coefficient (1198962) was

obtained as follows

1198962=120587

4119873

Ga119861 (1)

where 119873 is the number of IDT finger pairs and Ga and 119861are radiation resistance and susceptance respectively [28]Figure 5 shows the electromechanical coupling coefficientsof devices with different thicknesses of TiO

2thin films

Although TiO2thin film is not a piezoelectric material the

electromechanical coupling coefficients of devices increasewith increasing thicknesses due to the waveguide effect andthe maximum value is 038 at the 16-120583m thick TiO

2film

00 05 10 15 20 255

10

15

20

25

30

Thickness (120583m)

TCF

(ppm

∘C)

Figure 6 Temperature coefficients of frequency of devices withdifferent thicknesses of TiO

2thin films

The temperature coefficients of frequency (TCF) werecalculated by substituting the center frequencies at 30 50 and70∘C into the following equation

TCF =119865 (70∘C) minus 119865 (30∘C)40 times 119865 (50

∘C) (2)

Figure 6 shows the TCFs of devices with different thicknessesof TiO

2thin films The 90∘ rotated 42∘451015840 ST-cut quartz

reported in the literature showed a relatively high TCF about+30 ppm∘C [16] This TCF value decreases by means of aTiO2layer with a low TCF value and reduces to +66 ppm∘C

at 25-120583m thick TiO2film

33 Characteristics of the LoveWave Ultraviolet PhotodetectorThe band gap of TiO

2thin film with anatase phase is about

32 eV carriersrsquo concentrations are increased when the TiO2

thin film is exposed to UV illumination When Love wave


00 05 10 15 20 25

00

05

10

15

20

25

30

Inse

rtio

n lo

ss sh

ift (d

B)

Thickness (120583m)

Figure 7 Insertion loss shifts of devices with different thicknessesof TiO

2thin films after 365 nm UV illumination for 30 seconds

00 05 10 15 20 25

00

05

10

15

20

25

30

35

40

45

Phas

e shi

ft (d

eg)

Thickness (120583m)

Figure 8 Phase shifts of devices with different thicknesses of TiO2

thin films after 365 nm UV illumination for 30 seconds

is transmitted in a guiding layer the variations in electricalproperties of the guiding layer affect the characteristics ofwave propagation sensitively The wave velocity will decreasewhen the guiding layer becomes a higher conducting filmdue to the capacitance increasing and insertion loss of trans-mission signal will shift due to the variation of impedance[16] Figure 7 shows the insertion loss shifts with differentthicknesses of TiO

2thin films after 365 nm UV illumination

for 30 seconds The maximum change is 281 dB at the 135-120583m thick TiO

2film The main vibration and transmission

of Love wave is in the interface between the guiding layerand substrate The over thick guiding layer may be reducingand slowing the variations of conductivity in the interfaceFigure 8 shows the phase shifts with different thickness ofTiO2thin film after 365 nm UV illumination for 30 seconds

The maximum phase shift is 355 degree at the 135-120583m thickTiO2film Compare ZnO thin film of our previous results

as the same structure and IDT pattern the maximum phaseshift of 10-120583m thick ZnO film after 30 seconds under 365 nm

UV illumination was below 1 degree [23] The TiO2thin film

provides the good potential for Love wave UV photodetectorapplication

4 Conclusions

The Love wave ultraviolet photodetector that used TiO2

thin film and 90∘ rotated 42∘451015840 ST-cut quartz substratewas proposed The effect of thickness of TiO

2thin film on

the phase velocity electromechanical coupling coefficienttemperature coefficient of frequency and ultraviolet sensi-tivity of device was investigated Although TiO

2thin film is

not a piezoelectric material the electromechanical couplingcoefficient increases from 010 of blank quartz substrate to038 at the 16-120583m thick TiO

2film deposited due to the

waveguiding effect The temperature coefficient of frequencydecreases with increasing thickness of TiO

2thin film The

ultraviolet sensitivity is affected sensitively by the thicknessof the TiO

2thin film the maximum insertion loss shift and

phase shift are 281 dB and 355 degree at the 135-120583m thickTiO2film

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The authors would like to thank the National Science Councilof China Taiwan for financially supporting this researchunder Grant no NSC-101-2221-E-150-044

References

[1] M H Habibi N Talebian and J Choi ldquoThe effect of annealingon photocatalytic properties of nanostructured titanium diox-ide thin filmsrdquo Dyes and Pigments vol 73 no 1 pp 103ndash1102007

[2] C Sarra-Bournet C Charles andR Boswell ldquoLow temperaturegrowth of nanocrystalline TiO

2films with ArO

2low-field

helicon plasmardquo Surface and Coatings Technology vol 205 no15 pp 3939ndash3946 2011

[3] H Rath P Dash T Som et al ldquoStructural evolution of TiO2

nanocrystalline thin films by thermal annealing and swift heavyion irradiationrdquo Journal of Applied Physics vol 105 no 7 ArticleID 074311 2009

[4] A K Pradhan D Hunter J B Dadson et al ldquoStructural evo-lution of TiO

2nanocrystalline thin films by thermal annealing

and swift heavy ion irradiationrdquo Applied Physics Letters vol 86Article ID 222503 2005

[5] J E Lyon M K Rayan M M Beerbom and R Schlaf ldquoElec-tronic structure of the indium tin oxidenanocrystalline anatase(TiO2)ruthenium-dye interfaces in dye-sensitized solar cellsrdquo

Journal of Applied Physics vol 104 no 7 Article ID 0737142008

[6] A Fujishima K Hashimoto and TWatanabe TiO2Photocatal-

ysis Fundamentals and Applications BKC Tokyo Japan 1999[7] D Wojcieszak M Mazur M Kurnatowska et al ldquoInfluence of

Nd-doping on photocatalytic properties of TiO2nanoparticles


and thin film coatingsrdquo International Journal of Photoenergyvol 2014 Article ID 463034 10 pages 2014

[8] Y Nakano T Morikawa T Ohwaki and Y Taga ldquoDeep-level optical spectroscopy investigation of N-doped TiO

2filmsrdquo

Applied Physics Letters vol 86 no 13 Article ID 132104 2005[9] H C Chang M J Twu C Y Hsu R Q Hsu and C G Kuo

ldquoImproved performance for dye-sensitized solar cells using acompact TiO

2layer grown by sputteringrdquo International Journal

of Photoenergy vol 2014 Article ID 380120 8 pages 2014[10] X Kong C Liu W Dong et al ldquoMetal-semiconductor-metal

TiO2ultraviolet detectors with Ni electrodesrdquo Applied Physics

Letters vol 94 no 12 Article ID 123502 2009[11] W Zhang Q Li and W Liu ldquoSome influencing factors on

photocatalytic activity of TiO2film prepared using sol-gel

methodrdquo Advanced Materials Research vol 433ndash440 pp 362ndash366 2012

[12] E Gyorgy G Socol E Axente I NMihailescu C Ducu and SCiuca ldquoAnatase phase TiO

2thin films obtained by pulsed laser

deposition for gas sensing applicationsrdquoApplied Surface Sciencevol 247 no 1ndash4 pp 429ndash433 2005

[13] S Biswas K Prabakar T Takahashi T Nakashima Y Kubotaand A Fujishima ldquoStudy of photocatalytic activity of TiO

2

thin films prepared in various Ar O2ratio and sputtering gas

pressurerdquo Journal of Vacuum Science and Technology A vol 25no 4 pp 912ndash916 2007

[14] Q Ye P Y Liu Z F Tang and L Zhai ldquoHydrophilic propertiesof nano-TiO

2thin films deposited byRFmagnetron sputteringrdquo

Vacuum vol 81 no 5 pp 627ndash631 2007[15] O van Overschelde G Guisbiers F Hamadi A Hemberg

R Snyders and M Wautelet ldquoAlternative to classic annealingtreatments for fractally patterned TiO

2thin filmsrdquo Journal of

Applied Physics vol 104 no 10 Article ID 103106 2008[16] C K Campbell Surface Acoustic Wave Devices for Mobile

and Wireless Communications Academic Press New York NYUSA 1998

[17] D S Ballantine R M White S J Martin et al Acoustic WaveSensors-Theory Design and Physico-Chemical Applications Aca-demic Press New York NY USA 1997

[18] J Du G L Harding J A Ogilvy P R Dencher and M LakeldquoA study of Love-wave acoustic sensorsrdquo Sensors and ActuatorsA vol 56 no 3 pp 211ndash219 1996

[19] Z Zhang ZWen andCWang ldquoInvestigation of surface acous-tic waves propagating in ZnO-SiO

2-Si multilayer structurerdquo

Ultrasonics vol 53 no 2 pp 363ndash368 2013[20] Y Wang S Y Zhang F M Zhou L Fan Y Yang and C

Wang ldquoLove wave hydrogen sensors based on ZnO nanorodfilm36YX-LiTaO

3substrate structures operated at room tem-

peraturerdquo Sensors and Actuators B Chemical vol 158 no 1 pp97ndash103 2011

[21] N Barie U Stahl and M Rapp ldquoVacuum-deposited wave-guiding layers on STW resonators based on LiTaO

3substrate

as love wave sensors for chemical and biochemical sensing inliquidsrdquo Ultrasonics vol 50 no 6 pp 606ndash612 2010

[22] K Kalantar-Zadeh W Woldarski Y Y Chen B N Fry andK Galatsis ldquoNovel Love mode surface acoustic wave basedimmunosensorsrdquo Sensors and Actuators B Chemical vol 91 no1ndash3 pp 143ndash147 2003

[23] WWater and R-Y Jhao ldquoApplication of ZnO nanorods synthe-sized on 64∘ Y-cut LiNbO

3to surface acoustic wave ultraviolet

photodetectorrdquo Sensors and Actuators B Chemical vol 173 pp310ndash315 2012

[24] G LHarding and J Du ldquoDesign and properties of quartz-basedLove wave acoustic sensors incorporating silicon dioxide andPMMA guiding layersrdquo Smart Materials and Structures vol 6no 6 pp 716ndash720 1997

[25] H Pang Y Fu Z Li et al ldquoLove mode surface acoustic waveultraviolet sensor using ZnO films deposited on 36∘ Y-cutLiTaO

3rdquo Sensors and Actuators A Physical vol 193 pp 87ndash94

2013[26] A Talbi F Sarry M Elhakiki et al ldquoZnOquartz structure

potentiality for surface acoustic wave pressure sensorrdquo Sensorsand Actuators A Physical vol 128 no 1 pp 78ndash83 2006

[27] T Tsai S ChangWWeng et al ldquoA visible-blind TiO2nanowire

photodetectorrdquo Journal of the Electrochemical Society vol 159no 4 pp J132ndashJ135 2012

[28] W R Smith H M Gerard J H Collins T M Reeder and H JShaw ldquoAnalysis of interdigital surface wave transducers by useof an equivalent circuitmodelrdquo IEEETransactions onMicrowaveandTheory Techniques vol 17 no 11 pp 856ndash864 1969

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


morphologies and nanostructures [25 26] But ZnO filmpresents a poor stability in the acid or alkaline solutionsTiO2thin films and TiO

2nanowires have been applied for

various types of UV photodetectors [10 27] but the reportsof Love wave type were few The requirements of guidinglayer for a Love wave device application are being rigiddense and stable and having low radiation loss AlthoughTiO2is not a piezoelectric material its strong mechanical

and chemical stability excellent photoelectric activity andease of synthesizing the various surface morphologies withnanostructures provide the potential as the guiding andsensing layer for Love wave sensors applications

2 Experimental

The Love wave devices were fabricated on ST-cut (42∘451015840)quartz substrates (12mm times 13mm times 05mm) with a propa-gation direction perpendicular to the crystallographic 119909-axis(90∘ rotated) The input and output interdigital transducers(IDTs) consisted of 30 finger pairs with an electrode widthof 10 120583m and separation of 10 120583m yielding a periodicityof 40 120583m The IDT aperture was 4mm and the center tocenter of separation was 62mm The IDTs were made of200 nm sputtered titanium After the contact electrode ofIDTs with a protection the TiO

2films were deposited by RF

magnetron sputtering using a TiO2target (999) In the film

deposition process sputtering power was 350W sputteringpressure was 133 Pa O

2Ar ratio was 025 distance between

substrate and target was 70mm and the substrate was notheatedThe deposition rates were controlled at approximately170 nmhour Figure 1 presents the structure and pattern ofthe Love wave device

The crystalline structure and orientation of the TiO2

films were examined by X-ray diffraction (XRD) (ShimadzuXRD-6000) The surface morphology of the TiO

2films was

analyzed using field-emission scanning electron microscopy(FESEM) (Hitachi S4800-I) and atomic force microscopytechniques (DI D3100) Frequency response phase of trans-mitted signals wave velocities electromechanical couplingcoefficients UV responses and temperature coefficients offrequency of Love wave devices were measured by thenetwork analyzer (Agilent E5062A) The error bars werecalculated as two devices with the same parameters formeasuring three times respectively

3 Results and Discussion

31 Crystalline Structure and Surface Morphology Figure 2presents the XRD patterns of TiO

2thin films with different

thicknesses deposited on quartz substrates The TiO2thin

film at 135-120583m thickness shows an anatase structure andthe major reflection planes are (101) (004) (112) (200) and(211) respectivelyThe films at 050- and 160-120583m thicknessespresent an amorphous structure Figure 3 shows the SEMimages of TiO

2films with various thicknesses The surface

morphology is transferred greatly due to the filmsrsquo thicknessThe 050-120583m thick TiO

2thin film has a smooth surface and

a small columnar size When thickness reaches 085 and

Output IDTQuartz

Input IDT

TiO2 thin film

(a) Top view

Output IDTQuartz

Input IDTTiO2 thin film

(b) Cross-sectional view

Figure 1 Structure of the Love wave device

20 30 40 50 60

Inte

nsity

(au

)

(101)(004)

(112)(200)

(211)

160120583m

135120583m

085120583m

050120583m

2120579 (∘)

Figure 2 XRD patterns of TiO2thin films with various thicknesses

Table 1 The root mean square values and phase velocities of TiO2thin films deposited on quartz substrate with various thicknesses

Thickness(120583m)

Root mean square value(nm)

Phase velocity(ms)

050 047 4907085 284 4814135 334 4787160 587 4725250 1081 4356

135 120583m the polyhedrons with a sharp shape are grown onthe surface and the columnar size increases obviously Thesurface roughness of films turns into rough with increasingthickness The root mean square values of surface roughnessare presented in Table 1

32 Love Wave Device with TiO2Guiding Layer Figure 4

shows the frequency response and phase of transmitted signal(S21) for device with a 16-120583m thick TiO

2film The phase

velocity of a blank ST-cut (42∘451015840) quartz for X-propagationis 5060ms the phase velocity decreases with increasingthickness of TiO

2thin film and approaches 4356ms for








sert

ion

loss

(dB)

Frequency (MHz)

minus4000

minus4500

minus5000

minus5500

minus6000

minus6500

minus7000

minus7500

minus8000

minus8500

minus9000




25000

000

15000

10000

5000

20000

Phas

e (de

g)

Frequency (MHz)

minus5000

minus10000

minus15000

minus20000

minus25000

118126979MHz minus39519m∘




2film

00 05 10 15 20 25 3000

01

02

03

04

05

Thickness (120583m)

K2

()


2thin films



obtained as follows

1198962=120587

4119873

Ga119861 (1)


2thin films



2film

00 05 10 15 20 255

10

15

20

25

30

Thickness (120583m)

TCF

(ppm

∘C)


2thin films



∘C) (2)










00 05 10 15 20 25

00

05

10

15

20

25

30

Inse

rtio

n lo

ss sh

ift (d

B)

Thickness (120583m)



00 05 10 15 20 25

00

05

10

15

20

25

30

35

40

45

Phas

e shi

ft (d

eg)

Thickness (120583m)












4 Conclusions



2thin film on


2thin film is




2thin film The






Acknowledgment


References



2films with ArO

2low-field















2filmsrdquo













2



















3substrate























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of








sert

ion

loss

(dB)

Frequency (MHz)

minus4000

minus4500

minus5000

minus5500

minus6000

minus6500

minus7000

minus7500

minus8000

minus8500

minus9000




25000

000

15000

10000

5000

20000

Phas

e (de

g)

Frequency (MHz)

minus5000

minus10000

minus15000

minus20000

minus25000

118126979MHz minus39519m∘




2film

00 05 10 15 20 25 3000

01

02

03

04

05

Thickness (120583m)

K2

()


2thin films



obtained as follows

1198962=120587

4119873

Ga119861 (1)


2thin films



2film

00 05 10 15 20 255

10

15

20

25

30

Thickness (120583m)

TCF

(ppm

∘C)


2thin films



∘C) (2)










00 05 10 15 20 25

00

05

10

15

20

25

30

Inse

rtio

n lo

ss sh

ift (d

B)

Thickness (120583m)



00 05 10 15 20 25

00

05

10

15

20

25

30

35

40

45

Phas

e shi

ft (d

eg)

Thickness (120583m)












4 Conclusions



2thin film on


2thin film is




2thin film The






Acknowledgment


References



2films with ArO

2low-field















2filmsrdquo













2



















3substrate























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


sert

ion

loss

(dB)

Frequency (MHz)

minus4000

minus4500

minus5000

minus5500

minus6000

minus6500

minus7000

minus7500

minus8000

minus8500

minus9000




25000

000

15000

10000

5000

20000

Phas

e (de

g)

Frequency (MHz)

minus5000

minus10000

minus15000

minus20000

minus25000

118126979MHz minus39519m∘




2film

00 05 10 15 20 25 3000

01

02

03

04

05

Thickness (120583m)

K2

()


2thin films



obtained as follows

1198962=120587

4119873

Ga119861 (1)


2thin films



2film

00 05 10 15 20 255

10

15

20

25

30

Thickness (120583m)

TCF

(ppm

∘C)


2thin films



∘C) (2)










00 05 10 15 20 25

00

05

10

15

20

25

30

Inse

rtio

n lo

ss sh

ift (d

B)

Thickness (120583m)



00 05 10 15 20 25

00

05

10

15

20

25

30

35

40

45

Phas

e shi

ft (d

eg)

Thickness (120583m)












4 Conclusions



2thin film on


2thin film is




2thin film The






Acknowledgment


References



2films with ArO

2low-field















2filmsrdquo













2



















3substrate























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


00 05 10 15 20 25

00

05

10

15

20

25

30

Inse

rtio

n lo

ss sh

ift (d

B)

Thickness (120583m)



00 05 10 15 20 25

00

05

10

15

20

25

30

35

40

45

Phas

e shi

ft (d

eg)

Thickness (120583m)












4 Conclusions



2thin film on


2thin film is




2thin film The






Acknowledgment


References



2films with ArO

2low-field















2filmsrdquo













2



















3substrate























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




2filmsrdquo













2



















3substrate























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

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