Structure and mechanism of the formation of core–shell nanoparticles obtained through a one-step gas-phase synthesis by electron beam evaporation

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# Structure and mechanism of the formation of core–shell nanoparticles obtained through a one-step gas-phase synthesis by electron beam evaporation

Andrey V. Nomoev *1,2, Sergey P. Bardakhanov 1,3,4, Makoto Schreiber 1,
Dashima G. Bazarova 1, Nikolai A. Romanov 1, Boris B. Baldanov 1, Bair R. Radnaev 1

and Viacheslav V. Syzrantsev 3

Full Research Paper [Open Access](http://www.beilstein-journals.org/bjnano/about/openAccess.htm)

Address:
1Department of Physics and Engineering, Buryat State University,
Smolina street 24a, Ulan-Ude, 670000, Russia, 2 Institute of Physical

Materials Science, Siberian Branch of the Russian Academy of
Sciences, Sakhyanova str. 6, Ulan-Ude, 670047, Russia, 3 Institute of

Theoretical and Applied Mechanics, Siberian Branch of the Russian

Academy of Sciences, Institutskaya str. 4/1, Novosibirsk, 630090,
Russia and 4 Department of Physics, Novosibirsk State University,

Pirogova street 2, Novosibirsk, 630090, Russia

Email:
Andrey V. Nomoev * [- nomoevav@mail.ru](mailto:nomoevav@mail.ru)

- Corresponding author

Keywords:

core–shell; electron beam evaporation; gas phase; mechanism of

formation; one-step

_Beilstein J. Nanotechnol._ 2015, _6,_ 874–880.

[doi:10.3762/bjnano.6.89](http://dx.doi.org/10.3762%2Fbjnano.6.89)

Received: 29 December 2014

Accepted: 11 March 2015

Published: 31 March 2015

Associate Editor: S. R. Cohen

License and terms: see end of document.

## Abstract

The structure of core–shell Cu@silica and Ag@Si nanoparticles obtained in one-step through evaporation of elemental precursors

by a high-powered electron beam are investigated. The structure of the core and shell of the particles are investigated in order to

elucidate their mechanisms of formation and factors affecting the synthesis. It is proposed that the formation of Cu@silica particles

is mainly driven by surface tension differences between Cu and Si while the formation of Ag@Si particles is mainly driven by

differences in the vapour concentration of the two components.

## Introduction

Core–shell type nanoparticles are a type of biphasic materials

which have an inner core structure and an outer shell made

of different components. These particles have been of

interest as they can exhibit unique properties arising from the

combination of core and shell material, geometry, and design

[1,2]. Additionally, they have been designed so that the shell

material can improve the reactivity, thermal stability, or oxida
tive stability of the core material or to use an inexpensive core

material to carry a thin, more-expensive shell material [1,2].

Thus, they have found wide applicability in fields such

874

as biomedicine, electrical and semiconducting materials, and

catalysts [1,2].

The majority of core–shell particles are synthesised using solu
tion methods and usually involve two steps: synthesis of the

core structure followed by coating the core structure with the

shell material. Gas-phase synthesis techniques exist and usually

involve chemical vapour deposition (CVD) or pulsed laser

deposition (PLD) [1,2]. However these techniques also involve

multiple steps, usually depositing the shell material onto an

already formed core structure, and use substrates [3-5]. For

these established techniques, the mechanisms of formation have

been investigated and the various parameters which affect the

particle formation are known [1,6]. Recently, the authors have

synthesized core–shell Ag–Si and Cu–Si type particles in a new

way using electron beam evaporation [7,8]. In this method, the

core–shell particles are synthesized in one-step directly from the

gas phase without substrates. The precursors used are elemental

materials rather than chemical compounds which are degraded

into the final core or shell materials. Thus, this method may also

be a more economical method of synthesising certain types of

core–shell particles. Previous nanopowders synthesized with

this method have been produced at kg/h rates [9-11]. As single
step synthesis of core–shell materials from elemental gas phase

precursors has, to the authors’ knowledge, never been per
formed before, the mechanism of formation and the factors

influencing the synthesis are unknown. Thus, the current work

attempts to use data from the two synthesized Ag@Si and

Cu@silica particles to elucidate the mechanism by which the

core–shell nanoparticles may form. As the electron beam evap
oration method is a high-energy method, the reaction cannot be

observed as it occurs. Thus, the resultant particles are character
ized in-depth in order to illuminate how they formed. This work

can aid future researchers hoping to produce new types of

core–shell particles using the electron beam evaporation

method.

_Beilstein J. Nanotechnol._ 2015, _6,_ 874–880.

## Results and Discussion

Structure of Cu@silica particles

In the original work [7], XRD analysis on the bulk Cu@silica

samples revealed Cu, Cu2O, and CuO phases in the powder. A
TEM micrograph of the synthesized Cu@silica nanoparticles is

shown in Figure 1a. The average particle size was 119 ± 73 nm.

A higher magnification image of the shell and core structure is

shown in Figure 1b. In Figure 1b, it can clearly be seen that the

shell structure is amorphous and much less dense than the core

structure and some crystal planes are clearly visible in the core

structure. SAED measurements were performed on various

areas of the core structure and throughout the core, Cu(111)

was measured. The core structure was also measured after

5 years of storing the particles at atmospheric conditions in a

non-airtight container and the core structure was unchanged;

indicating that the shell structure is very effective at preventing

contact of the Cu core with oxygen. An XRD of the Cu@silica

powders from a different batch which contained less copper

oxides is shown in Supporting Information File 1, Figure S1.

Some particle cores, when observed with the correct focus and

electron beam strength exhibited ring structures indicative

of multiple contact twinning as shown clearly in Figure 2

(also seem in one particle in Figure 1a). This reveals that

the core structure consists of domains of monocrystals

rather than randomly oriented polycrystalline grains or a single

monocrystal.

The shell thickness was about 11 nm for most particles. As the

shell is amorphous, it was not possible to measure its crystallo
graphic structure. There were also a few small particles not

connected to a core which had the same contrast as the shell

material on the TEM. When EDX measurements of the

core–shell particles were measured, Cu, Si, and O were

measured. EDX measurements performed on the “unbound”

shell material measured Si and O. The relative atomic compos
ition of the shell material was about 64% Si and 36% O. Thus,

Figure 1: TEM micrograph of the Cu@silica nanoparticles. a) Overview, b) detail of the core and shell structure.

875

_Beilstein J. Nanotechnol._ 2015, _6,_ 874–880.

Figure 2: TEM micrograph of a Cu@silica nanoparticle. a) Bright field, b) dark field.

the shell is likely a mixture of amorphous Si, SiO, and SiO2. As
the argon atmosphere in which the particles were synthesized is

considered quite pure, the oxidation of the shell for the

Cu@silica particles but lack of it in the Ag@Si particles

suggests that the majority of the oxygen likely originated from

the starting copper ingot which is known to contain some

oxygen. As Si has a higher affinity for oxygen than Cu, oxygen

released by the evaporation of the copper or dissolved in the

copper would be taken up by the silicon during particle forma
tion. From HRTEM images, it is clear that the shells are not

completely spherical and have some roughness (lumps) in their

structure. This may result from either small solid Si particles

agglomerating onto the core, onto an already formed shell, or

disturbances to the shell as it was forming by the surrounding

environment. Some clumps of different contrast were also

observed on the surface of some shells and were identified to be

CuO and Cu2O by SAED measurements. Thus, after formation
of the shell, some copper had also adsorbed onto the shell

surface. These were likely oxidized after the nanoparticles were

exposed to the air.

In addition to the core–shell particles, a few particles were

observed with very uneven or possibly incomplete shells

(Figure 3). These particles had spots with what appeared to be

moiré patterns; interference patterns which form due to differ
ences in the lattice orientation between two crystal planes.

Moiré patterns can occur due to two identical planes being

rotated with respect to one another, two parallel planes with

dissimilar spacings, or a combination of the two. SAED

measurements on these regions showed the presence of

Cu(111), Cu2O(111), and a moiré spacing of 1.3100 nm. The
moiré spacing, _D_, between two phases can be calculated by

(1)

Figure 3: TEM micrograph of a Cu particle with an incomplete shell demonstrating moiré patterns where Cu2O has grown on the Cu. a) View of whole
particle, b) detail of the moiré patterns.

876

where _d_ 1 and _d_ 2 are the interplanar spacings of the two phases
and α is the angle between the two lattices [12]. Fitting the

measured moiré spacing to the moiré spacing calculated based

on the measured d-spacings, a relative angle of α = 0.093° was

fitted. Thus, the upper layer is essentially parallel to the bottom

plane. It is known that the minimal value of the crystal forma
tion and surface energy is obtained when a crystal plane grows

on a substrate of the same crystal structure. As the crystal struc
ture of both of Cu and Cu2O are cubic and the moiré patterns
are caused by parallel planes, this suggests that Cu2O(111) grew
epitaxially onto the exposed Cu(111). Although it can not be

determined definitively from the 2-dimentional TEM images, it

may be possible that the Cu2O grew in holes in the shell. It is
unknown when the Cu2O formed – during or after the experiment but as the rest of the core structure was not further

oxidized, the “patching” of the holes may have protected the

core from further oxidation. As only (111) planes were

measured on the moiré patterns, the multiple contact twinned

structure of the core is further supported.

Structure of Ag@Si particles

An X-ray diffractogram of the Ag@Si particles is shown in

Supporting Information File 1, Figure S2, showing only crys
talline silver. A TEM image of the synthesized Ag@Si parti
cles is shown in Figure 4. In general, the powder synthesized

from the Ag–Si system contained a lower yield of Ag@Si

spherical core–shell particles compared to the Cu–Si system and

more interconnected and deformed silver agglomerates. Addi
tionally, in general, the shell structures were much thinner and

more uneven on the Ag@Si particles compared to the

Cu@silica particles. Thus, this indicates a lower affinity of the

shell for the core. The core was confirmed to be crystalline Ag

with no intermixing of Si and the shell was still amorphous Si.

Figure 4: TEM micrograph of the Ag@Si nanoparticles along with Ag
agglomerates.

_Beilstein J. Nanotechnol._ 2015, _6,_ 874–880.

In some Ag@Si particles, interesting patterns were observed but

they were not as regular as on the Cu@silica particles and were

not thought to be due to twinning defects. The cause of these

patterns is still unknown. The average particle size in the

Ag@Si system is 11 ± 10 nm, much smaller than the Cu@silica

particle sizes.

Formation of Cu@silica particles

According to calculations in [13], the main reasons multi
component particles form into core–shell structures is either a

drive to decrease the surface energy of the system or differ
ences in the atomic sizes of the component materials.

In the case of the Cu–Si system, the difference in covalent

radius between Cu (132 pm) and Si (111 pm) is insignificant

and thus size effects are not considered relevant for this system.

In many cases, the surface tension of a liquid has a temperature

dependence of the form

(2)

which is valid for a certain temperature range above the melting

temperature ( _T_ m) of the material where σ( _T_ m) is the surface
tension at the melting point of the material and _d_ σ/ _dT_ is the rate

of change of the surface tension with temperature [14]. The

empirical dependence of the surface tension of copper with

temperature is

(3)

[15]. The surface tension of silicon varies as

(4)

[16]. Below the melting point, when the materials are solid,

the surface energy is the solid equivalent of the surface tension.

The surface energy values for Cu and Si are 1830 and
1230 mN m −1, respectively [17]. The dependence of the surface

tension and energy of Si, Cu, and Ag with temperature are

plotted in Figure 5. As can be seen, at all temperatures, the

surface tension of Cu is significantly higher than that of Si.

Thus, reduction of the surface energy of the particles by coating

Cu with Si is likely to be the main driving force for making the

Si–Cu vapour condense into Cu@silica particles.

A mechanism of formation of Cu@silica particles can be

proposed considering that both the melting and boiling

temperatures of Si are higher than that of Cu ( _T_ b(Si) = 3538 K,

877

Figure 5: Graph of the dependence of the surface tension of Si, Cu,
and Ag with temperature.

_T_ b(Cu) = 2835 K) as is the surface tension. It is reasonable to
assume that as the mixed vapour cools, droplets of Cu and Si

condense from the gas phase and come into contact. In the

aggregated droplets, the silicon atoms will segregate to the

surface of the droplet due to the difference in surface tension.

During this segregation process, the silicon will react with any

oxygen dissolved inside the droplet or in the atmosphere to

form SiO2 as Si has a higher affinity for oxygen than Cu. The
silicon on the surface will then solidify long before the inner

copper to form the shell; the amorphous nature resulting from

the SiO2. This solid shell around the liquid copper allows the
Cu to crystallize undisturbed from the outer atmosphere;

forming multiple contact twinned structure instead of polycrys
tals. Excess Si and Cu which did not form into mixed droplets

may later agglomerate onto the shell surface; the adsorbed

copper oxidizing when the powder is exposed to air. Particles

with moiré patterns may form when insufficient Si droplets mix

with Cu; leaving uncovered areas on the copper that could be

oxidized.

The variations in the particle sizes of the Cu@silica particles

are thought to be due to local fluctuations in the vapour concen
tration of Cu and Si. Fluctuations in local vapour concentra
tions can easily occur from the carrier gas flow and convection

currents in the Cu–Si liquid being evaporated. As the thickness

of the silica shell is relatively constant compared to the particle

sizes, this suggests that the silica shell stops the growth of the

core Cu. Thus areas containing higher Si concentrations would

form smaller core–shell particles while in areas with lower Si

concentrations, the Cu core would grow larger before the

growth was halted by the shell formation.

Formation of Ag@Si particles
In the case of the Ag–Si system, the atomic radii ( _r_ Ag = 145 pm
and _r_ Si = 111 pm) are also not significantly different. As seen
from Figure 5 (using

_Beilstein J. Nanotechnol._ 2015, _6,_ 874–880.

(5)

[18] and a surface energy of Ag of 1250 mN m −1 [17]), the

surface tension of Ag and Si are extremely close. Thus, neither

atomic size effects nor surface tension effects are likely to be re
sponsible for the formation of core–shell structures.

In initial experiments with the Ag–Si system, the beam current

was varied for the evaporation of the target. It was found that

core–shell particles were only obtained at a beam current of

4 mA. At higher beam currents of 5 and 7 mA, core–shell

nanoparticles were not created but instead large Ag particles

with small Si particles adsorbed onto them. Therefore, it seems

likely that the relative concentration of Ag and Si in the evapo
rated vapour played a key role in the formation of core–shell

structures. As the vapour pressure of Ag (100 kPa at 2433 K

[19]) is higher than that of Si (100 kPa at 3537 K [19]), at

higher beam currents, the Si:Ag vapour ratio would decrease.

Only at the beam current of 4 mA was the Si content in the

vapour sufficient to create the core–shell particles. Due to the

relative thinness of the Si shell compared to the size of the core

structure, the lack of free Si particles found in the sample, and

the high number of deformed or interconnected Ag particles, it

is thought that the vapour in the reported experiment still

contained a higher portion of Ag compared to Si. The ratio of Si

to Ag was also varied and core–shell particles only formed with

higher Si to Ag ratios; supporting the need for sufficient Si in

the vapour phase for core–shell structure formation. The carrier

gas flow rate was varied as well but mainly affected the particle

sizes, with smaller particles forming with higher flow rates due

to faster cooling of the vapour.

Based on this information, the following mechanism of forma
tion for the Ag@Si particles is proposed: Initially, particles of

Si and Ag condense from the vapour. As the Si concentration is

low in the vapour, only very small amorphous Si particles form

while larger crystalline Ag particles are able to form. No inter
mixing occurs as Si has an extremely low solubility in Ag (the
maximum solubility being 4 × 10 –4 at % at 1623 K [20]). Due

to van der Waal interactions, the particles agglomerate. As the

relative size of the Ag particles are much larger compared to the

Si particles, the Si tends to agglomerate onto the surface of the

Ag particles. However, as the Si particle concentration is low,

many Ag particles are not fully covered and thus uncovered

areas of the Ag agglomerate with other exposed Ag on other

particles.

The size distribution of the Ag@Si particles was much smaller

than that of the Cu@silica particles. However, for the Ag–Si

system many larger Ag agglomerates were found along with the

878

core–shell particles. Due to the limited amount of Si, only

the smaller Ag particles could be coated fully by the Si to form

complete core–shell particles; narrowing the Ag@Si size

distribution.

## Conclusion

The structure and mechanism of formation of Cu@silica and

Ag@Si core–shell nanoparticles synthesized using high
powered electron beam evaporation were investigated. While

the mechanism of formation differ between the systems, in

general, the main factors causing core–shell structure formation

are the relative vapour concentration of the materials, surface

tension differences, and differences in melting temperature of

the component materials. Besides changing the precursor ma
terials, the main experimental parameters that can affect the for
mation of core–shell particles is the electron beam strength. The

formation of the Cu@silica core–shell nanoparticles is thought

to predominantly be driven by surface tension differences

between the core and shell material at the melting temperature

of the shell. In this mechanism, it was important that the shell

material solidify before the core material to create these struc
tures. In the case of the Ag@Si system, the relative concentra
tion of the two elements in the vapour was thought to be the

most important parameter; the low concentration Si thinly

adsorbing onto the surface of larger Ag particles. These results

may guide the synthesis of future core–shell type particles

through the electron-beam evaporation method.

## Experimental

The principle of operation of the experimental setup for

producing the Cu@silica and Ag@Si composite nanoparticles

and schematics of the device are given in [7,8]. Briefly, an

ELV-6 industrial electron accelerator was used to produce an

electron beam to evaporate the chosen materials. The acceler
ator allows the electron beam to be released into a non-vacuum

environment with an electron energy of 1.4 MeV, beam

current of up to 75 mA, and beam power density of up to
5 × 10 6 W/cm 2 . A crucible was filled with the materials to be

evaporated. For the synthesis of Cu@silica particles, Si and Cu

were placed in a graphite crucible with a weight ratio of 20:1

with Cu on the bottom. The Ag@Si particles were synthesized

with a Si:Ag weight ratio of 10:1 with Ag on the bottom. The

materials were irradiated by the electron beam first, at a low

current to melt the materials, then at a higher current to evapo
rate them. The heating rate could reach as much as 1000 K/min

and the surface temperature of the melt could reach 5000 K.

Throughout the experiment, Ar gas was flowed through the

evaporation chamber and carried the evaporation gasses to

a condensation chamber where the nanoparticles were formed

and then through a filter from which the nanoparticles were

collected.

_Beilstein J. Nanotechnol._ 2015, _6,_ 874–880.

The characterization of the nanoparticles was carried out by

transmission electron microscopy (TEM), high-resolution TEM

(HRTEM), selective area electron diffraction (SAED), and

energy dispersive X-ray fluorescence (EDX) analysis. These

measurements were performed on a JEM-2010 TEM (JEOL,

Japan, 200 kV accelerating voltage, 0.14 nm resolution)

equipped with an EDX (EDAX Co.) spectrometer (130 eV

energy resolution, 1 nm spatial resolution). To perform the

measurements, the core–shell nanopowders were diluted in

ethanol, subjected to ultrasonic dispersion, and precipitated onto

a carbon film fixed to a copper grid.

## Supporting Information

Supporting Information File 1

XRD analysis.

[[http://www.beilstein-journals.org/bjnano/content/](http://www.beilstein-journals.org/bjnano/content/supplementary/2190-4286-6-89-S1.pdf)

[supplementary/2190-4286-6-89-S1.pdf]](http://www.beilstein-journals.org/bjnano/content/supplementary/2190-4286-6-89-S1.pdf)

## Acknowledgements

This study was performed as part of the Ministry of Education

and Science of the Russian Federation contract No.

16.1930.2014/K.

## References

1. Chaudhuri, R. G.; Paria, S. _Chem. Rev._ 2012, _112,_ 2373–2433.

[doi:10.1021/cr100449n](http://dx.doi.org/10.1021%2Fcr100449n)

2. Srdić, V. V.; Mojić, B.; Nikolić, M.; Ognjanović, S.

_Process. Appl. Ceram._ 2013, _7,_ [45–62. doi:10.2298/PAC1302045S](http://dx.doi.org/10.2298%2FPAC1302045S)

3. Sahu, G.; Wang, K.; Gordon, S. W.; Zhou, W.; Tarr, M. A. _RSC Adv._

2012, _2,_ [3791–3800. doi:10.1039/c2ra01030e](http://dx.doi.org/10.1039%2Fc2ra01030e)

4. Ishii, M.; Kato, H.; Hashimoto, I.; Homma, Y. _Mater. Express_ 2013, _3,_

[355–359. doi:10.1166/mex.2013.1137](http://dx.doi.org/10.1166%2Fmex.2013.1137)

5. Ishii, M.; Kato, H.; Hashimoto, I.; Homma, Y. _Mater. Express_ 2014, _4,_

[135–143. doi:10.1166/mex.2014.1154](http://dx.doi.org/10.1166%2Fmex.2014.1154)

6. van Embden, J.; Jasieniak, J.; Gómez, D. E.; Mulvaney, P.; Giersig, M.

_Aust. J. Chem._ 2007, _60,_ [457–471. doi:10.1071/CH07046](http://dx.doi.org/10.1071%2FCH07046)

7. Temuujin, J.; Bardakhanov, S. P.; Nomoev, A. V.; Zaikovskii, V. I.;

Minjigmaa, A.; Dugersuren, G.; Van Riessen, A. _Bull. Mater. Sci._ 2009,

_32,_ [543–547. doi:10.1007/s12034-009-0081-1](http://dx.doi.org/10.1007%2Fs12034-009-0081-1)

8. Nomoev, A. V.; Bardakhanov, S. P. _Tech. Phys. Lett._ 2012, _38,_

[375–378. doi:10.1134/S1063785012040268](http://dx.doi.org/10.1134%2FS1063785012040268)

9. Lysenko, V. I.; Bardakhanov, S.; Korchagin, A.; Kuksanov, N.;

Lavrukhin, A.; Salimov, R.; Fadeev, S.; Cherepkov, V.; Veis, M.;

Nomoev, A. _Bull. Mater. Sci._ 2011, _34,_ 677–681.

[doi:10.1007/s12034-011-0181-6](http://dx.doi.org/10.1007%2Fs12034-011-0181-6)

10.Bardakhanov, S. P.; Korchagin, A. I.; Kuksanov, N. K.;

Lavrukhin, A. V.; Salimov, R. A.; Fadeev, S. N.; Cherepkov, V. V.

_Mater. Sci. Eng., B_ 2006, _132,_ 204–208.

[doi:10.1016/j.mseb.2006.02.038](http://dx.doi.org/10.1016%2Fj.mseb.2006.02.038)

11.Bardakhanov, S. P.; Korchagin, A. I.; Kuksanov, N. K.;

Lavrukhin, A. V.; Salimov, R. A.; Fadeev, S. N.; Cherepkov, V. V.

_Dokl. Phys._ 2006, _51,_ [353–356. doi:10.1134/S1028335806070044](http://dx.doi.org/10.1134%2FS1028335806070044)

879

12.Orlov, L. G.; Usikov, M. P.; Utevski, L. M. _Sov. Phys. Usp._ 1962, _76,_

[109–152. doi:10.3367/UFNr.0076.196201e.0109](http://dx.doi.org/10.3367%2FUFNr.0076.196201e.0109)

13.Ivanov, A. C.; Borisov, C. A. _Poverkhnost_ 1982, _10,_ 140–145.

14.Keene, B. J. _Int. Mater. Rev._ 1993, _38,_ 157–192.

[doi:10.1179/imr.1993.38.4.157](http://dx.doi.org/10.1179%2Fimr.1993.38.4.157)

15.Brillo, J.; Egry, I. _J. Mater. Sci._ 2005, _40,_ 2213–2216.

[doi:10.1007/s10853-005-1935-6](http://dx.doi.org/10.1007%2Fs10853-005-1935-6)

16.Shishkin, A. V.; Basin, A. S. _Theor. Found. Chem. Eng._ 2004, _38,_

[660–668. doi:10.1007/s11236-005-0043-2](http://dx.doi.org/10.1007%2Fs11236-005-0043-2)

17.Aqra, F.; Ayyad, A. _Appl. Surf. Sci._ 2011, _257,_ 6372–6379.

[doi:10.1016/j.apsusc.2011.01.123](http://dx.doi.org/10.1016%2Fj.apsusc.2011.01.123)

18.Kucharski, M.; Fima, P. _Monatsh. Chem._ 2005, _136,_ 1841–1846.

[doi:10.1007/s00706-005-0393-9](http://dx.doi.org/10.1007%2Fs00706-005-0393-9)

19.Stull, D. In _American Institute of Physics Handbook,_ 3rd ed.;

Grey, D. E., Ed.; McGraw Hill: New York, NY, USA, 1972.

20.Oleslnski, R. W.; Gokhale, A. B.; Abbaschlan, G. J.

_Bull. Alloy Phase Diagrams_ 1989, _10,_ 635–640.

[doi:10.1007/BF02877631](http://dx.doi.org/10.1007%2FBF02877631)

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