research article synthesis of fe nanoparticles...

Research ArticleSynthesis of Fe Nanoparticles Functionalized with Oleic AcidSynthesized by Inert Gas Condensation

L G Silva1 F Solis-Pomar1 C D Gutieacuterrez-Lazos1 Manuel F Meleacutendrez2 E Martinez3

A Fundora4 and E Peacuterez-Tijerina1

1 Facultad de Ciencias Fısico-Matematicas Universidad Autonoma de Nuevo Leon 66451 San Nicolas de los Garza NL Mexico2Hybrid Materials Laboratory (HML) Department of Materials Engineering (DIMAT) Faculty of EngineeringUniversity of Concepcion 270 EdmundoLarenas Casilla 160-C 4070409 Concepcion Chile

3 Centro de Investigacion en Materiales Avanzados S C Unidad Monterrey-PIIT 66600 Apodaca NL Mexico4 Instituto de Ciencia y Tecnologıa deMateriales (IMRE) Universidad de LaHabana Zapata y G Vedado CP 10400 LaHabana Cuba

Correspondence should be addressed to E Perez-Tijerina eduardopereztjuanledumx

Received 17 March 2014 Revised 30 July 2014 Accepted 30 July 2014 Published 18 September 2014

Academic Editor Renyun Zhang

Copyright copy 2014 L G Silva 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

In this work we study the synthesis of monodispersed Fe nanoparticles (Fe-NPs) in situ functionalized with oleic acid Thenanoparticles were self-assembled by inert gas condensation (IGC) technique by using magnetron-sputtering process Structuralcharacterization of Fe-NPs was performed by transmission electron microscopy (TEM) Particle size control was carried outthrough the following parameters (i) condensation zone length (ii) magnetron power and (iii) gas flow (Ar and He) Typicallythe nanoparticles generated by IGC showed diameters which ranged from sim07 to 20 nm Mass spectroscopy of Fe-NPs in thedeposition system allowed the study of in situ nanoparticle formation through a quadrupole mass filter (QMF) that one can usetogether with a mass filter When the deposition system works without quadrupole mass filter the particle diameter distribution isaround +minus20 When the quadrupole is in line then the distribution can be reduced to around +minus2

1 Introduction

In the last decades nanotechnology research has increasedconsiderably This is an interdisciplinary area which includesphysics [1] chemistry [2] biochemistry [3] molecular biol-ogy [4] medicine [5] optoelectronic devises [6] and proteinengineering [7] among others The objectives of nanotech-nology are the study the understanding and the controlof the matter at atomic and molecular level The investi-gation in nanotechnology has been centered principally insurface modified nanoparticles [8] advanced administrationin medicaments [9] transistors [10] interfaces with bio-logical entities [11] and other areas of the integration ofnanosystems or nanoelectronics with biological entities asthe oriented to the delivery of active biological entities [12]and processing manipulation and detection of molecules orbiological complexes [13] Size control of the nanostructureallows obtaining newmaterials with functional and structural

size-dependent properties At this point the research hasfocused basically on alloys and nanostructured composites[14] advanced functional polymeric materials [15] advancedfunctional nanostructured materials and the incorporationof ordered molecular systems or nanoparticles in adequatesubstrates However the size control shape stability anddispersibility of NPs in desired solvents are still a techno-logical challengeTherefore providing proper surface coatingand developing some effective protection strategies to keepthe stability of NPs are very important An unavoidableproblem associated with particles in this size range is theirintrinsic instability over longer periods of time Such smallparticles tend to form agglomerates that reduce the energyassociated with the high surface area to volume ratio of thenanosized particles Moreover naked metallic nanoparticlesare chemically highly active and are easily oxidized in airresulting generally in loss of magnetism and dispersibilitysuch as iron nanoparticles For many applications it is crucial

Hindawi Publishing CorporationJournal of NanomaterialsVolume 2014 Article ID 643967 6 pageshttpdxdoiorg1011552014643967

2 Journal of Nanomaterials

Substrate manipulator

View ports

Quadrupolarmass filter

Nanocluster source(sputtering) (ECI)

Introduction chamber

Turbomolecular pump

1000 ltsMBE deposition ports

Turbomolecular pump300 lts (differential vaccum)

2998400998400 800∘C

Figure 1 Integral system to synthesize Fe nanoparticles (image taken from Nanosys500 Manual [17])

Aggregation zone

Linear actuator

Filtering zone

Deposition zone

QuadrupoleChamber deposition

Sputtering zone

10minus1 Torr

Figure 2 Schematic diagram of the nanocluster source

to develop protection strategies to chemically stabilize thenaked magnetic nanoparticles against degradation duringor after the synthesis These strategies comprise grafting ofor coating with organic species including surfactants orpolymers or coating with an inorganic layer such as silicaor carbon It is noteworthy that in many cases the protectingshells not only stabilize the nanoparticles but also can beused for further functionalization depending on the desiredapplication [16]

A new generation of analysis instruments and fabricationat nanometric scale has been developed for example thesystem for the deposition and nanoparticle characterizationfrom Mantis Deposition System (Nanosys500) [17] whichallows obtaining nanoparticles with a controlled size rangingfrom 20 atoms up to 20 nm Chemical methods have asprincipal advantage their low cost but they have asmain defi-ciency their difficulty to obtain nanoparticles with low sizedispersion Only under strict conditions (inert atmospheresshort reflux times and reaction temperatures) it is possibleto obtain nanoparticles with a small deviation in their size[18] Conversely in a chemical synthesis it has nanoparticleswith sizes ranging from 5 nm to 100 nm and this representsa technological disadvantage considering that nanoparticleproperties aremainly associatedwith their size Another defi-ciency is the difficulty in growing nanoparticles with morethan one component for example bimetallic nanoparticleswhere it is necessary to have a precise and strict control of the

chemical composition On the contrary the use of physicalmethods enables obtaining stoichiometric nanoparticles withcontrolled size and shape [14] However the high cost of thesesystems represents their main disadvantage

This paper presents the results concerned with toostructural and chemical characterization of Fe nanoparticlessynthesized in the inert gas condensation system MantisNanosys500 and deposited on silicon substrates

2 Experimental Details

Nanoparticles were prepared by the inert gas condensation(IGC) technique [19ndash21] using theNanosys500 system (Man-tis Deposition Ltd) that employs sputtering technique asion source [17] The experimental set-up employed in thiswork for the production of size-selected Fe clusters is shownin Figure 1 In this figure one can see the main parts ofthe system it has a nanocluster source that includes a DCmagnetron-sputtering unit and the turbo molecular pump(300 Ls) a quadrupolemass filter and a deposition chamberThe nanocluster source is the heart of the system to obtain theFe nanoparticles this has a device called Nanogen 50 wherenanoclusters are produced and then they are channeled to themain deposition chamber to deposit them on the substrate asillustrated in Figure 2

In the gas-phase condensation technique a cathodicerosion system is used with a DC magnetron to generate the

Journal of Nanomaterials 3

supersaturated metallic vapor The size-selected Fe nanopar-ticles deposition takes place through four main processessputtering aggregation filtering and deposition In the gas-phase condensation technique a cathodic erosion system isused with a DC magnetron to generate the supersaturatedmetallic vapor The size of the nanoparticles can be modifiedby three parameters (i) condensation zone length (that canbe varied from 30 to 150mm) (ii) magnetron power (rangingfrom 25 to 100W) and (iii) flow of gases (Ar and Hepartial pressure 1-2 times 10minus1 Torr) The condensation zone isdefined as the distance between themagnetron head (erosionzone) and the first expansion aperture this condensationzone can be modified by means of a linear drive actuatorreducing or increasing the distance between the magnetronhead and the first expansion aperture and in the same waythe accretion of the nanoparticle can be varied in time oncethe supersaturated vapor metal is aggregated due to theincreasing or decreasing of residence time for nanoparticleson the aggregation zone Another parameter that modifiesthe nanoparticle size is the magnetron power with highermagnetron power the sputtered atoms density from the targetincreases leading to an increase of nanoparticle size Thisrelation has a linear increase as the saturation regime isreached where an increment in power decreases slightlythe nanoparticle size The last parameter to modify thenanoparticle size is the gas flow (Ar and He) where Ar isused as erosion gas By increasing the Ar flow the metalvapor pressure increases When He gas was introduced inthe chamber (which was used as carrier gas) and its flowwas increasing the NPs size is reduced this reduction isassociated with the collisions between the nanoparticles andthe He molecules thus the mean free path of nanoparticles isreduced diminishing their size

The Fe nanoparticles were deposited on Si substrateswith and without oleic acid covering in their surface TheSi substrates without oleic acid were sonicated in tolueneto obtain a solution of Fe nanoparticles The Si substrateswith oleic acid were sonicated in toluene the product wasflocculated by adding ethanol and separated by centrifuga-tion decanting the supernatantTheprecipitatewas dispersedin toluene The particles were characterized by transmissionelectron microscopy (TEM) In order to retain their crys-talline characteristics and optical and electrical propertiesthe kinetic energy of nanoparticles was controlled by theenergy cluster impact (ECI) technique [22 23] and theenergy of acceleration was kept at 01 eV per atom in thenanoparticle assuring a soft landing of nanoparticles on thesubstrate In order to obtain monodispersed nanoparticlesthe deposition time was few minutes up to 30 minutes

3 Results

Among the advantages that Nanosys500 system can offerwe can mention for example that cluster distribution canbe varied and the nanocluster source can be calibrated foroptimum performance in order to select the wished clustersize The results of mass spectrum analysis for 1 3 4 5and 6 nm Fe nanoparticles are displayed in Figure 3 The

0 1 2 3 4 5 6 7 8 9

minus04

minus02

00

02

04

06

08

10

12

Cou

nts

Diameter (nm)

1nm2nm3nm

4nm5nm6nm

Figure 3 Mass spectrometry profiles for Fe nanoparticles ofdifferent sizes (before the selection by mass)

16

14

12

10

08

06

04

1 2 3 4 5 6 7 8

Diameter (nm)

Freq

uenc

y (a

u)

Fe-Nps

Figure 4 Mass spectra of filtered Fe-Nps (5 nm) obtained by IGCtechnique

different mass profiles represent the capability of the inertgas condensation technique to prepare nanoparticles with ahigh resolved distribution size and hence we can study theirelectrical morphological and optical properties based on theFe nanoparticle size Figure 4 displays the mass spectrum ofFe nanoparticles deposited on the Si substrates measured inthe quadrupole mass spectrometer

TEM image of filtered 5 nm nanoparticle was acquiredto obtain the size distribution of deposited nanoparticlesas shown in Figure 5(a) In this figure it is possible todistinguish a monodispersed size distribution of Fe nanopar-ticles centered at 5 nm Nanoparticles were filtered throughthe quadrupole mass spectrometer A high magnificationmicrography is presented in Figure 5(b) The histogram inFigure 5(c) let us analyze the measured mean size whichdemonstrates the narrow size dispersion in filtered nanopar-ticle size at 5 nmwith a central value in 51 nm demonstrating


(a) (b)

0

10

20

30

40

50

60

3 4 5 6 7 8 9 10 11 12

Freq

uenc

y

Diameter (nm)

(c)

Figure 5 (a) Micrography of Fe nanoparticles deposited on Si substrate (b) A magnified micrography of a Fe nanoparticle (c) Histogramcorresponding to deposited Fe nanoparticles obtained from TEM analysis

(a) (b)

Figure 6 TEM images of Fe nanoparticles coated with oleic acid deposited by IGC

the effectiveness of inert gas condensation technique toobtain nanoparticles of predetermined size

Figure 6 shows TEM images of Fe nanoparticles coatedwith oleic acid deposited by IGC We can see that particles

show high uniformity in a nearly spherical shape withthe average diameter of 5 nm After surface modificationthe nanoparticles maintained their original spherical shapeswithout any deformation or coalescence due to particles


(nm)

(110)

(200)

60

50

40

30

20

10

0

80

70

60

50

40

30

202nm

014 nm

(a) (b)

05 10

05 10

024 nm

Figure 7 Iron nanoparticles coated with oleic acid obtained in the experiments The crystallographic distances found by the nanoparticleprofile (right) correspond to (100) and (200) planes of cubic Fe (metal)

aggregation and are self-organized in a hexagonal arrange-ment confirming that nanoparticle surface has been sta-bilized Oleic acid is widely used in ferrite nanoparticlesynthesis because it can form dense protective monolayersproducing therefore highly uniform in shape and monodis-perse nanoparticles

Figure 7 shows the iron nanoparticles obtained in theexperiments the indexing was performed by Carine 31 soft-ware The crystallographic distances found by the nanopar-ticle profile (right) correspond to (100) and (200) planesof cubic Fe (metal) according to the crystallographic chartwith reference code 00-006-0696 Phases corresponding tooxides or other materials based on iron were not evidencedthis proves the efficiency of the stabilization method used inthis work whose distribution size shape and oxidation werecontrolled

Figure 8 shows the background subtracted energy lossspectra for the Fe nanoparticles with and without oleic acidThe label K indicates the energetic position of the oxygen K1selector binding energy L2 and L3 define the 2p12 and 2p32binding energy of iron respectively [24]

The slight increase of intensity that can be seen at energiesabove the L3 edge is caused by electron scattering processesThe shift indicates the presence of metallic Fe for the oleicacid capped nanoparticles [25 26]

4 Conclusions

From previous results we can say that monodispersed Fenanoparticles were obtained The inert gas condensationtechnique allows us to prepare in situ oleic acid capped Fe

L2

L3

400

300

200

100

0

minus100

minus200550 600 700 750 800

Loss energy

FeFe-oleic

Oxygen

Figure 8 The background subtracted energy loss spectra for the Fenanoparticles with and without oleic acid

nanoparticles with a high resolved distribution size Dueto the oleic acid stabilization iron nanoparticles were self-organized in hexagonal arrays This result opens a path forsome possible applications catalysis chemical biomedicalelectronic biological and so forthDue the nature of this kindof applications it is essential to countwith a high control gradefor the particle size We were able to obtain Fe nanoparticleshighly stabilized with the oleic acid molecule with a focalizedsize distribution Phases corresponding to oxides or other


materials based on ironwere not observed demonstrating theefficiency of the stabilization method used in this work

Conflict of Interests

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

Acknowledgment

This work was economically supported by CONACYT Mex-ico

References

[1] A S Edelstein and R C Cammarata Nanoparticle SynthesisProperties and Applications Institute of Physics PublishingBristol UK 1996

[2] G SchmidNanoscale Materials in Chemistry Wiley New YorkNY USA 2001

[3] R J Puddephat The Chemistry of Gold Elsevier AmsterdamThe Netherlands 1978

[4] C M Niemeyer ldquoNanoparticles proteins and nucleic acidsbiotechnology meets materials sciencerdquo Angewandte ChemiemdashInternational Edition vol 40 no 22 pp 4128ndash4158 2001

[5] L Olofsson T Rindzevicius I Pfeiffer M Kall and F HookldquoSurface-based gold-nanoparticle sensor for specific and quan-titative DNA hybridization detectionrdquo Langmuir vol 19 no 24pp 10414ndash10419 2003

[6] T Ogawa K Kobayashi G Masuda T Takase and S MaedaldquoElectronic conductive characteristics of devices fabricatedwith 110-decanedithiol and gold nanoparticles between 1-120583melectrode gapsrdquo Thin Solid Films vol 393 no 1-2 pp 374ndash3782001

[7] S-J Park A A Lazarides C A Mirkin and R L LetsingerldquoDirected assembly of periodic materials from protein andoligonucleotide-modified nanoparticle building blocksrdquo Ange-wandte Chemie International Edition vol 40 pp 2909ndash29122001

[8] K Kimura S Sato and H Yao ldquoParticle crystals of surfacemodified gold nanoparticles grown from waterrdquo ChemistryLetters no 4 pp 372ndash373 2001

[9] D H Brown andW E Smith ldquoThe chemistry of the gold drugsused in the treatment of rheumatoid arthritisrdquoChemical SocietyReviews vol 9 no 2 pp 217ndash240 1980

[10] B H Schneider E L Dickinson M D Vach J V Hoijer andL V Howard ldquoOptical chip immunoassay for hCG in humanwhole bloodrdquo Biosensors and Bioelectronics vol 15 no 11-12 pp597ndash604 2000

[11] M Zheng F Davidson and X Huang ldquoEthylene glycolmonolayer protected nanoparticles for eliminating nonspecificbinding with biological moleculesrdquo Journal of the AmericanChemical Society vol 125 no 26 pp 7790ndash7791 2003

[12] B Nolting J J Yu G Y Liu S J Cho S Kauzlarichand J Gervay-Hague ldquoSynthesis of gold glyconanoparticlesand biological evaluation of recombinant Gp120 interactionsrdquoLangmuir vol 19 no 16 pp 6465ndash6473 2003

[13] C Zhang Z Zhang B Yu J Shi and X Zhang ldquoApplicationof the biological conjugate between antibody and colloid Aunanoparticles as analyte to inductively coupled plasma mass

spectrometryrdquo Analytical Chemistry vol 74 no 1 pp 96ndash992002

[14] S Bharathi ldquoSol-gel-derived nanocrystalline gold-silicate com-posite biosensorrdquo Analytical Communications vol 35 no 1 pp29ndash31 1998

[15] J H Park Y T LimOO Park andY C Kim ldquoEnhancement ofphotostability in blue-light-emitting polymers doped with goldnanoparticlesrdquoMacromolecular Rapid Communications vol 24no 4 pp 331ndash334 2003

[16] A-H Lu E L Salabas and F Schuth ldquoMagnetic nanoparticlessynthesis protection functionalization and applicationrdquoAnge-wandte ChemiemdashInternational Edition vol 46 no 8 pp 1222ndash1244 2007

[17] MantisDeposition LimitedOxfordUK httpwwwmantisde-positioncom

[18] R W J Scott A K Datye and R M Crooks ldquoBimetallicpalladium-platinum dendrimer-encapsulated catalystsrdquo Jour-nal of the American Chemical Society vol 125 no 13 pp 3708ndash3709 2003

[19] E Perez-Tijerina M Gracia Pinilla S Mejıa-Rosales UOrtiz-Mendez A Torres and M Jose-Yacaman ldquoHighly size-controlled synthesis of AuPd nanoparticles by inert-gas con-densationrdquo Faraday Discussions vol 138 pp 353ndash362 2008

[20] K Sattler J Muhlbach and E Recknagel ldquoGeneration of metalclusters containing from 2 to 500 atomsrdquo Physical ReviewLetters vol 45 no 10 pp 821ndash824 1980

[21] D Reinhard B D Hall D Ugarte and R Monot ldquoSize-independent fcc-to-icosahedral structural transition in unsup-ported silver clusters an electron diffraction study of clus-ters produced by inert-gas aggregationrdquo Physical Review BmdashCondensed Matter and Materials Physics vol 55 no 12 pp7868ndash7881 1997

[22] H Haberland Z Insepov and M Moseler ldquoMolecular-dynamics simulation of thin-film growth by energetic clusterimpactrdquo Physical Review B vol 51 no 16 pp 11061ndash11067 1995

[23] O Rattunde M Moseler A Hafele J Kraft D Rieser and HHaberland ldquoSurface smoothing by energetic cluster impactrdquoJournal of Applied Physics vol 90 no 7 pp 3226ndash3231 2001

[24] T P Huelser HWiggers P Ifeacho O Dmitrieva G Dumpichand A Lorke ldquoMorphology structure and electrical propertiesof iron nanochainsrdquoNanotechnology vol 17 no 13 article 5 pp3111ndash3115 2006

[25] R D Leapman L A Grunes and P L Fejes ldquoStudy of the L23

edges in the 3d transition metals and their oxides by electron-energy-loss spectroscopy with comparisons to theoryrdquo PhysicalReview B vol 26 no 2 pp 614ndash635 1982

[26] Y Jin H Xu and A K Datye ldquoElectron Energy Loss Spec-troscopy (EELS) of iron Fischer-Tropsch catalystsrdquo Microscopyand Microanalysis vol 12 no 2 pp 124ndash134 2006

Submit your manuscripts athttpwwwhindawicom

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NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


Substrate manipulator

View ports

Quadrupolarmass filter

Nanocluster source(sputtering) (ECI)

Introduction chamber

Turbomolecular pump

1000 ltsMBE deposition ports

Turbomolecular pump300 lts (differential vaccum)

2998400998400 800∘C

Figure 1 Integral system to synthesize Fe nanoparticles (image taken from Nanosys500 Manual [17])

Aggregation zone

Linear actuator

Filtering zone

Deposition zone

QuadrupoleChamber deposition

Sputtering zone

10minus1 Torr

Figure 2 Schematic diagram of the nanocluster source

to develop protection strategies to chemically stabilize thenaked magnetic nanoparticles against degradation duringor after the synthesis These strategies comprise grafting ofor coating with organic species including surfactants orpolymers or coating with an inorganic layer such as silicaor carbon It is noteworthy that in many cases the protectingshells not only stabilize the nanoparticles but also can beused for further functionalization depending on the desiredapplication [16]

A new generation of analysis instruments and fabricationat nanometric scale has been developed for example thesystem for the deposition and nanoparticle characterizationfrom Mantis Deposition System (Nanosys500) [17] whichallows obtaining nanoparticles with a controlled size rangingfrom 20 atoms up to 20 nm Chemical methods have asprincipal advantage their low cost but they have asmain defi-ciency their difficulty to obtain nanoparticles with low sizedispersion Only under strict conditions (inert atmospheresshort reflux times and reaction temperatures) it is possibleto obtain nanoparticles with a small deviation in their size[18] Conversely in a chemical synthesis it has nanoparticleswith sizes ranging from 5 nm to 100 nm and this representsa technological disadvantage considering that nanoparticleproperties aremainly associatedwith their size Another defi-ciency is the difficulty in growing nanoparticles with morethan one component for example bimetallic nanoparticleswhere it is necessary to have a precise and strict control of the

chemical composition On the contrary the use of physicalmethods enables obtaining stoichiometric nanoparticles withcontrolled size and shape [14] However the high cost of thesesystems represents their main disadvantage

This paper presents the results concerned with toostructural and chemical characterization of Fe nanoparticlessynthesized in the inert gas condensation system MantisNanosys500 and deposited on silicon substrates

2 Experimental Details

Nanoparticles were prepared by the inert gas condensation(IGC) technique [19ndash21] using theNanosys500 system (Man-tis Deposition Ltd) that employs sputtering technique asion source [17] The experimental set-up employed in thiswork for the production of size-selected Fe clusters is shownin Figure 1 In this figure one can see the main parts ofthe system it has a nanocluster source that includes a DCmagnetron-sputtering unit and the turbo molecular pump(300 Ls) a quadrupolemass filter and a deposition chamberThe nanocluster source is the heart of the system to obtain theFe nanoparticles this has a device called Nanogen 50 wherenanoclusters are produced and then they are channeled to themain deposition chamber to deposit them on the substrate asillustrated in Figure 2

In the gas-phase condensation technique a cathodicerosion system is used with a DC magnetron to generate the




3 Results


0 1 2 3 4 5 6 7 8 9

minus04

minus02

00

02

04

06

08

10

12

Cou

nts

Diameter (nm)

1nm2nm3nm

4nm5nm6nm


16

14

12

10

08

06

04

1 2 3 4 5 6 7 8

Diameter (nm)

Freq

uenc

y (a

u)

Fe-Nps





(a) (b)

0

10

20

30

40

50

60

3 4 5 6 7 8 9 10 11 12

Freq

uenc

y

Diameter (nm)

(c)


(a) (b)






(nm)

(110)

(200)

60

50

40

30

20

10

0

80

70

60

50

40

30

202nm

014 nm

(a) (b)

05 10

05 10

024 nm






4 Conclusions


L2

L3

400

300

200

100

0

minus100

minus200550 600 700 750 800

Loss energy

FeFe-oleic

Oxygen







Acknowledgment


References




































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






3 Results


0 1 2 3 4 5 6 7 8 9

minus04

minus02

00

02

04

06

08

10

12

Cou

nts

Diameter (nm)

1nm2nm3nm

4nm5nm6nm


16

14

12

10

08

06

04

1 2 3 4 5 6 7 8

Diameter (nm)

Freq

uenc

y (a

u)

Fe-Nps





(a) (b)

0

10

20

30

40

50

60

3 4 5 6 7 8 9 10 11 12

Freq

uenc

y

Diameter (nm)

(c)


(a) (b)






(nm)

(110)

(200)

60

50

40

30

20

10

0

80

70

60

50

40

30

202nm

014 nm

(a) (b)

05 10

05 10

024 nm






4 Conclusions


L2

L3

400

300

200

100

0

minus100

minus200550 600 700 750 800

Loss energy

FeFe-oleic

Oxygen







Acknowledgment


References




































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




(a) (b)

0

10

20

30

40

50

60

3 4 5 6 7 8 9 10 11 12

Freq

uenc

y

Diameter (nm)

(c)


(a) (b)






(nm)

(110)

(200)

60

50

40

30

20

10

0

80

70

60

50

40

30

202nm

014 nm

(a) (b)

05 10

05 10

024 nm






4 Conclusions


L2

L3

400

300

200

100

0

minus100

minus200550 600 700 750 800

Loss energy

FeFe-oleic

Oxygen







Acknowledgment


References




































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




(nm)

(110)

(200)

60

50

40

30

20

10

0

80

70

60

50

40

30

202nm

014 nm

(a) (b)

05 10

05 10

024 nm






4 Conclusions


L2

L3

400

300

200

100

0

minus100

minus200550 600 700 750 800

Loss energy

FeFe-oleic

Oxygen







Acknowledgment


References




































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







Acknowledgment


References




































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials










CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



research article synthesis of fe nanoparticles...

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