S uc u al effec s due o he inco po a ion o A a oms
in he la ice o Z O2 hin films p epa ed by ion beam
assis ed deposi ion
J.P. Holgado
a
, R. Escoba Galindo
b
, A. an Veen
b
, H. Schu
b
,
J.Th.M. de Hosson
c
, A.R. Gonz
aalez-Elipe
a,*
a
Ins i u o de Ciencia de Ma e iales de Se illa (CSIC/Uni e sidad de Se illa) and Dp o. de Qu
ıımica, Ino g
aanica Uni . Se illa.,
A . Ame ico Vespucio S/N, E-41092 Se illa, Spain
b
In e acul y Reac o Ins i u e, De ec s in Ma e ials, Del Uni e si y o Technology, Mekelweg 15, 2629 JB Del , The Ne he lands
c
Ma e ials Science Cen e , Uni e si y o G oningen, Nijenbo gh 4, 9747 AG G oningen, The Ne he lands
Recei ed 4 Oc obe 2001; ecei ed in e ised o m 27 Janua y 2002
Abs ac
Two se s o Z O2 hin films ha e been p epa ed a oom empe a u e by ion beam induced chemical apou de-
posi ion and subsequen ly annealed up o 1323 K. The wo se s o samples ha e been p epa ed by using ei he Oþ
2o
mix u es o (Oþ
2þA þ) ions o he decomposi ion o a ola ile me allo ganic p ecu so o zi conium. The s uc u e
and mic os uc u e o hese wo se s o samples ha e been de e mined by means o X- ay diff ac ion, Fou ie ans o m
in a ed spec oscopy and posi on beam analysis (PBA). The samples we e e y compac and dense and had a e y
low-su ace oughness. A e annealing in ai a TP573 K bo h se s o films we e anspa en and showed simila
e ac ion indexes.
Fo he (Oþ
2þA þ)-Z O2 hin films i is shown by X- ay pho oelec on spec oscopy and Ru he o d back sca e ing
ha a ce ain amoun o inco po a ed A (5–6 a .%) emains inco po a ed wi hin he oxide la ice. No changes we e
de ec ed in he amoun o inco po a ed A e en a e annealing a T¼773 K. Fo highe annealing empe a u es
(T>1073 K), he amoun o A s a s o dec ease, and a T¼1223 K only esidual amoun s o A (<0.4%) emain
wi hin he la ice. I has been ound ha as a as A a oms emain inco po a ed wi hin he Z O2ne wo k, he
(Oþ
2
–A þ)-Z O2films p esen a cubic/ e agonal phase. When he amoun o ‘‘embedded’’ A dec eases, he c ys alline
phase e e s o monoclinic, he majo i y phase obse ed o he (Oþ
2)-Z O2films a e any annealing ea men s.
The mic os uc u e o he films a e diffe en annealing ea men s has been in es iga ed by PBA. The p esence o
A ions and he ini ial amo phous s a e o he laye s we e de ec ed by his echnique. An inc ease o he open olume
was obse ed a e annealing up o 773 K in bo h se s o samples. Fo highe annealing empe a u es he samples
showed a p og essi e c ys allisa ion esul ing in a dec ease o he open olume. Du ing his sin e ing he samples
wi hou embedded A p esen a highe concen a ion o open olume de ec s. A e he elease o A occu s (TP1223
K) bo h samples app oach o a simila de ec ee s a e.
Nuclea Ins umen s and Me hods in Physics Resea ch B 194 (2002) 333–345
www.else ie .com/loca e/nimb
*
Co esponding au ho . Fax: +34-954-460-665.
E-mail add ess: [email p o ec ed] (A.R. Gonz
aalez-Elipe).
0168-583X/02/$ - see on ma e Ó2002 Else ie Science B.V. All igh s ese ed.
PII: S0168-583X(02)00695-X
The inco po a ion o A wi hin he Z O2 hin film s uc u e, is p oposed as he main ac o con ibu ing o he
s abilisa ion o he cubic/ e agonal phase o Z O2a oom empe a u e.
Ó2002 Else ie Science B.V. All igh s ese ed.
Keywo ds: Chemical apou deposi ion; Ion bomba dmen ; Thin film; Posi on annihila ion; Phase ans o ma ion; Ion assis ed
deposi ion; Z O2
1. In oduc ion
Among many o he applica ions, such as op i-
cal coa ings [1], buffe laye s o g owing supe -
conduc o s [2], hea esis an coa ings [3], oxygen
senso s [5], e c. ... , Z O2 hin films ha e a ac ed
g ea a en ion because o hei p ope ies as ion
conduc o s [4], o be used in he so-called solid
oxide uel cells (SOFCs) [5]. Fo all hese appli-
ca ions, and specially in he case o SOFCs, i is
gene ally desi able o ob ain he e agonal o
cubic phase o zi conia. I is known ha al hough
he e agonal phase o Z O2is uns able a oom
empe a u e, i can be s abilised by doping wi h
ca ions such as Y3þ,Ca
2þ, e c. [6], o by dec easing
he pa icle size o he c ys alline domains [7]. The
syn hesis o Z O2o Z O2doped hin films (i.e.
Z O2-M) has been a emp ed by many diffe en
me hods including sp ay deposi ion [8], chemical
apou deposi ion (CVD) [9], elec on e apo a ion
[10], and o he me hods [11].
Ve y compac Z O2ðMÞ hin films can be p e-
pa ed by ion beam assis ed deposi ion p ocedu es
(IBAD) [12] ha in ol e he bomba dmen o
he g owing film wi h low-ene gy ion beams (i.e.
gene ally EP1000 eV), usually Oþ
2,A
þo mix-
u es o bo h. By hese me hods, i is e y common
o obse e he appea ance o diffe en c ys allo-
g aphic effec s, such as amo phisa ion o he p e -
e en ial g ow h o some c ys allog aphic planes
[13,14] ha a e a ibu ed o he influence o he
bomba dmen wi h low-ene gy ions [15]. Ma in
[16] has shown ha monoclinic o e agonal phase
ans o ma ions can be induced in Z O2 hin films
by bomba dmen wi h A þions o ela i ely low
ene gy. Fo bulk Z O2 he effec o high-ene gy
A þbomba dmen in inducing c ys allog aphic
ans o ma ions and he s abilisa ion o he cubic/
e agonal phase is well known [17]. In mos cases
an implici explana ion o his ype o monoclinic
o cubic/ e agonal ans o ma ion elies on he
assump ion ha ballis ic in e ac ions be ween he
ene ge ic ions and he a ge a oms a e esponsi-
ble o he phase change. The esul s p esen ed
in he p esen pape do no exac ly suppo such
an explana ion based on ene ge ic effec s, bu a-
he emphasise he ole o A embedded wi hin
he Z O2 hin film in p oducing he s abilisa ion
o he cubic/ e agonal phase. We compa e he
s uc u al e olu ion o Z O2 hin films p epa ed
by ion beam induced chemical apou deposi ion
(IBICVD) by using ei he Oþ
2o mixed Oþ
2þA þ
ion beams. In he la e case he cubic/ e agonal
phase is s abilised upon annealing, as long as A
a oms emain inco po a ed wi hin he hin films.
In a p e ious pape [18] we ha e s udied in de ail
how he ex u e, mo phology and op ical p ope -
ies o he esul ing films a e affec ed by he use o
A þions. The fi s mo i a ion o he p esen pa-
pe is hen o highligh how he p esence o in-
co po a ed A may s abilise he cubic/ e agonal
s uc u e o zi conia ac ing in a simila way han
‘‘doping’’ ca ions such as Y3þ,Ca
2þ, e c. and o
p o ide an analysis o he e olu ion o s uc u al
de ec s in he samples upon annealing, as de e -
mined by posi on beam analysis (PBA).
2. Expe imen al
Thin films ha e been p epa ed by IBICVD [19].
This me hod consis s o he decomposi ion o a
ola ile me allic p ecu so by means o an ion
beam. Fu he de ails abou he me hod as applied
o he syn hesis o oxides and ni ides can be ound
in p e ious publica ions [19–21].
Zi conium e a e -bu oxide, Z (Obu )4has
been used as p ecu so . Typical pa ial p essu e
334 J.P. Holgado e al. / Nucl. Ins . and Me h. in Phys. Res. B 194 (2002) 333–345
du ing deposi ion was 4 105mba . Oþ
2o mix-
u es o Oþ
2þA þions, accele a ed o 400 eV,
we e supplied by an ‘‘IQP’’ b oad ion sou ce.
O2þA mix u es wi h a mola a io 10:1 we e
used o p epa a ion o A -inco po a ed samples.
A beam cu en o a ound 40 lAcm
2was mea-
su ed a he sample holde du ing deposi ion. The
o al p essu e in he chambe du ing deposi ion
was 5 104mba . Unde hese condi ions a
g ow h a e o app oxima ely 2.0 nm min1was
measu ed wi h a qua z c ys al moni o a he
sample posi ion.
Silicon (1 0 0) wa e s and used qua z ha e
been used as subs a es o p epa a ion o he
samples.
X- ay diff ac ion (XRD) spec a we e eco ded
by using he Cu Ka adia ion wi h a Siemens
D5000 diff ac ome e . An incidence angle o 0.5°
was chosen o inc ease he sensi i i y.
IR spec a we e ob ained wi h a Nicole spec-
ome e a 8 cm1 esolu ion o samples p epa ed
on Si wa e s. The silicon subs a e was pa ially
anspa en o in a ed adia ion showing a small
ea u e a 609 cm1.
Annealing o he samples in ai was ca ied ou
in a con en ional a mosphe ic u nace, using a
linea hea ing amp o 10 K min1. A he end o
he amp he selec ed final empe a u e was kep
o 3 h ollowed by cooling down slowly.
Ru he o d back sca e ing (RBS) spec a we e
eco ded wi h a andem ion accele a o (Pelle on
9SH-2 om NEC) a he Cen o Nacional de
Acele ado es (CNA) in Se ille. Alpha pa icles o
2.021 MeV and usual se ings o sca e ing angle
and de ec o geome y we e used o eco ding o
spec a. The da a acquisi ion was done wi h a o al
sample cha ge o 5 lC. Simula ions o composi-
ion p ofiles ha e been done wi h he RUMP
p og am code [22].
X- ay pho oelec on spec oscopy (XPS) was
ca ied ou using an ESCALAB 210 spec ome e
wo king in pass ene gy cons an mode wi h a alue
o 50 eV. The su ace concen a ion o he ele-
men s was de e mined by measu ing he peak
a eas and co ec ing by he app op ia e sensi i i y
alues.
The PBA was pe o med using he Del a i-
able ene gy posi on beam (VEP) [23]. The posi-
ons we e injec ed in he samples wi h ene gies
be ween 100 eV and 25 keV. Annihila ion o pos-
i ons wi h elec ons esul s, in he cen e -o -mass
sys em, in he emision o wo collinea pho ons o
511 keV each. In he labo a o y ame he non-
ze o momen um o he posi on-elec on pai
causes an ene gy shi o he pho ons. This esul s
in a b oade ene gy dis ibu ion, called Dopple
b oadening o he annihila ion adia ion (DBAR)
a ound he 511 keV peak. This b oadened ene gy
spec um is cha ac e ised by wo pa ame e s: S
and W. The S(shape) pa ame e is defined as he
a io be ween he cen al a ea and he o al a ea o
he annihila ion pho opeak. This pa ame e e-
flec s he annihila ion o posi ons wi h alence
elec ons (low-momen um elec ons). In gene al, a
high alue o Sindica es posi on annihila ion in
open olume de ec s. I he ma e ial allows he
o ma ion o a Posi onium s a e (Ps) his will
con ibu e o he DBAR wi h a na ow componen
because o he low-in insic momen o he pa a-
posi onium. A second use ul pa ame e o he
analysis o DBAR is he W(wing) pa ame e ,
which eflec s he posi on annihila ion wi h high-
momen um elec ons (co e elec ons). The W-
pa ame e is sensi i e o changes in he chemical
en i onmen . Bo h pa ame e s can be combined in
S–W maps wi h a hi d a iable (e.g. he implan-
a ion ene gy, empe a u e o s ain) as a unning
pa ame e . These maps a e use ul o ace posi on
apping in, e.g., laye s as in he samples desc ibed
in his wo k. The da a was analysed wi h he
a iable ene gy posi on fi (VEPFIT) p og am
[24]. The samples s udied he e a e modelled by a
numbe o s acked slabs. Each o hese slabs is
cha ac e ised by a hickness (di), Siand Wipa-
ame e s, and a posi on diffusion leng h (Li). The
measu ed SðEÞand WðEÞas a unc ion o he
implan a ion ene gy E, a e a sum o he cha ac-
e is ic Siand Wi alues o he apping laye s
(clus e poin s) weigh ed by he ac ion o posi-
ons apped in each laye iðEÞ. The spec a we e
eco ded wi h a single Ge solid-s a e de ec o . All
expe imen s we e ca ied ou a oom empe a u e
unde a acuum o abou 106Pa. The alues o S
and Wpa ame e s a e no malised wi h espec o
he Sand W alues o a c ys al Si subs a e
(SSi ¼0:58, WSi ¼0:031).
J.P. Holgado e al. / Nucl. Ins . and Me h. in Phys. Res. B 194 (2002) 333–345 335
3. Resul s
3.1. Chemical composi ion
The de e mina ion o he chemical composi ion
o he zi conia films was done by XPS and RBS.
The pho oelec on spec a o bo h se o samples,
p epa ed by using Oþ
2o (Oþ
2þA þ) ions, we e
ypical o a Z O2s oichiome y. Besides a ca bon
peak, which is easily emo ed by bomba dmen
wi h A þo Oþ
2(and hus p o ing ha i is due o
con amina ion by exposu e o ai ), no o he con-
aminan species we e de ec ed a he su ace o
samples. In he case o (Oþ
2þA þ)-Z O2samples,
A 2p and A 2s peaks could be de ec ed in he
pho oelec on spec a o he films. Thei in ensi ies
we e equi alen o an a omic pe cen age o ap-
p oxima ely 5–6%, a alue ha did no change
a e cleaning by spu e ing wi h Oþ
2ions o 3 keV
ene gy. The samples we e also analysed by RBS o
ob ain a mo e p ecise quan i a i e de e mina ion
o he amoun o A p esen in he samples, as well
as an e alua ion o he chemical composi ion
p ofile o he whole film hickness. Fig. 1 shows
expe imen al and heo e ically calcula ed spec a
o he as p epa ed (Oþ
2þA þ)-Z O2and Oþ
2-
Z O2samples. The igh o his figu e shows, in an
enla ged scale, he A egion o some spec a
co esponding o (Oþ
2þA þ)-Z O2samples an-
nealed a inc easing empe a u es up o 1423 K. In
he (Oþ
2)-Z O2and (Oþ
2
–A þ)-Z O2samples he O/
Z a io was close o 2.0, al hough a sligh ly
smalle a io (i.e. ffi1.95–2.00) was ob ained o he
as p epa ed (Oþ
2
–A þ)-Z O2 hin film. Fo hese
samples, A (5–6 a .%) is ound o be dis ibu ed
homogeneously o e he whole film hickness e en
a e hei annealing a empe a u es as high as 873
K. A e annealing o he samples a T>773 K
he concen a ion o A wi hin he film dec eases.
I is ound ha a 1073 K only 3% o A is s ill
e ained by he hin film, and ha a smalle con-
cen a ion is obse ed a i s su ace. A e an-
nealing a 1323 K, only a 0.5 a .% o A is p esen ,
wi h an e en lowe concen a ion a he su ace o
he hin film. These esul s indica e ha annealing
ea men s abo e 1073 K p o oke a p og essi e
loss o he A inco po a ed wi hin he s uc u e o
zi conia films. This loss is mo e p onounced
om he opmos su ace laye s o he Z O2 hin
films.
Fig. 1. Expe imen al and simula ed RBS spec a o he (Oþ
2þA þ)-Z O2sample. The inse shows, in an enla ged scale, he egion
co esponding o embedded A a e annealing ea men s a indica ed empe a u es.
336 J.P. Holgado e al. / Nucl. Ins . and Me h. in Phys. Res. B 194 (2002) 333–345
3.2. C ys allog aphic s uc u e
Fig. 2 shows XRD pa e ns o (Oþ
2)-Z O2 hin
films p epa ed a 298 K and a e annealing a
inc easingly highe empe a u es up o 1323 K.
Fo compa ison, he e e ence pa e ns o he
mos in ense peaks o he diffe en phases o zi -
conia a e included in he op pa o he figu e. The
spec um o he as p epa ed (Oþ
2)-Z O2sample
e eal he exis ence o a leas wo phases: mono-
clinic and cubic and/o e agonal. I should be
ema ked he e ha he diff ac og ams co e-
sponding o hese wo phases p esen a se ies o
peaks wi h e y simila in ensi y and wi h e y
close posi ions. Due o he la ge wid h o he peaks
ob ained in he diag am o he hin film and he
possible displacemen o he posi ions o he peaks
espec o hose o he pu e phases due o s ess
and s ain effec s, e en a ca e ul analysis o he
posi ions o he peaks do no pe mi o disc imi-
na e be ween he cubic and/o he e agonal phase
o zi conia in he hin film. Thus, in he ollow-
ing discussion a men ion o cubic/ e agonal
phase should always be aken as a possible exis-
ence o any o hose phases o a mix u e o bo h.
Annealing a T<773 K leads o a ela i e in-
c ease o he monoclinic phase, al hough only a
small change in he wid h o he peaks is obse ed
in his ange o empe a u es. By con as , when
he samples a e annealed a highe empe a u es
(T>873 K), a d as ic dec ease is obse ed in he
in ensi y o he peaks associa ed wi h he cubic/
e agonal phase. These peaks p ac ically disap-
pea om he spec um when he film was an-
nealed a TP1223 K. This annealing ea men
induces an inc ease in he heigh and a dec ease in
he wid h o he peaks co esponding o he
monoclinic phase (Table 1). Fo he whole em-
pe a u e ange o annealing, he ela i e in ensi y
o he peaks o he monoclinic phase was a om
he a io obse ed in a single c ys al, hus indi-
ca ing he p e e en ial g ow h in he films o some
c ys allog aphic planes (c . Table 1).
XRD pa e ns o (Oþ
2þA þ)-Z O2films p e-
pa ed a 298K and subsequen ly annealed a in-
c easingly highe empe a u es up o 1323 K a e
p esen ed in Fig. 3. The XRD pa e n o he ‘‘as
deposi ed’’ (Oþ
2þA þ)-Z O2films depic s only wo
b oad ea u es a diff ac ion angles which sugges
he exis ence o a badly o de ed cubic o e agonal
s uc u e o Z O2. Again, he wid h o he peaks
makes i e y difficul o disc imina e be ween hese
wo phases, and in he ollowing discussion i
should always be kep in mind he possible exis-
ence o ei he cubic/ e agonal phases o e en a
mix u e o bo h. Al hough he posi ion o he di -
ac ion lines is consis en wi h hose o he cubic/
e agonal phases, he obse ed in ensi ies a e a
Fig. 2. XRD pa e ns o Oþ
2-Z O2 hin film o he as p epa ed
samples and a e annealing ea men s a indica ed empe a-
u es. The pa e ns o he mos in ense peaks o monoclinic
(bo om), cubic ( op, ull line) and e agonal ( op, dashed line)
phases o zi conia a e included o compa ison.
J.P. Holgado e al. / Nucl. Ins . and Me h. in Phys. Res. B 194 (2002) 333–345 337

om e e ence pa e ns. In pa icula , he high in-
ensi y o he peak a 2hffi59:4°, indica es a p e -
e en ial g ow h o he film acco ding o he
co esponding (3 1 1) planes o he cubic phase and/
o he (2 1 1) plane o he e agonal phase. The
p e e en ial g ow h o planes wi h high Mille in-
dices has been ecen ly epo ed by us o Fe2O3
hin films p epa ed also by IBICVD [25]. Such a
p e e en ial g ow h was ela ed wi h he p esence
o A embedded in he s uc u e.
By annealing hese zi conia samples a TP573
K he diff ac ion pa e n changed. The maximum
o he peak a 2h¼59:4°becomes sligh ly b oade
wi h a small asymme y a highe diff ac ion an-
gles. Simul aneously, a b oad ea u e appea s a
2h¼33–35°. The compa ison o hese s uc u es
wi h he lines co esponding o he e e ence pa -
e n o he bulk ma e ial, sugges s he exis ence o
a badly o de ed cubic/ e agonal phase o zi conia
in he as p epa ed samples and hei p og essi e
o de ing o es uc u ing wi h he annealing
ea men s.
A significan change in he diff ac ion diag am
o he (O2þA þ)-Z O2samples is obse ed a e
annealing a T¼1073 K. In his case he peak
co esponding o planes (3 1 1) is s ill he mos
in ense, bu becomes na owe (c . Table 2). In his
diag am peaks a 33–35°a e now clea ly isible,
p obably co esponding o some diff ac ion planes
o he cubic/ e agonal phase o zi conia and/o
(2 0 0) o he monoclinic phase. The peaks o he
e agonal/cubic phases o he zi conia a e no
longe isible a e annealing a T¼1223 K, being
subs i u ed by a clea pa e n co esponding o he
monoclinic phase. The diff ac ion peaks o his
phase a e also much na owe now (c . Table 2),
ha ing a ull wid h a hal maximum (FWHM)
simila o ha o he peaks o he (Oþ
2)-Z O2 hin
films epo ed in Fig. 2 (c . Table 1). A e an-
nealing a 1323 K, a diff ac ion diag am simila o
ha depic ed by he Oþ
2-Z O2sample annealed a
he same empe a u e was ob ained.
Fou ie ans o m in a ed spec oscopy
(FTIR) spec oscopy can be used as a complemen
o XRD o a mo e accu a e desc ip ion o he
s uc u e o Z O2 hin films. Al hough FTIR is
no mally used on a ‘‘finge p in ’’ basis, a sys em-
a ic analysis o IR spec a may also p o ide insigh
in o he Z O2 hin film s uc u e [25–29].
Fig. 4 shows FTIR spec a o he (Oþ
2)-Z O2
sample as p epa ed and a e diffe en annealing
ea men s up o 1323 K. Ini ially, he FTIR
spec a o he as p epa ed Oþ
2-Z O2film is cha -
ac e ised by a s uc u e whe e some b oad bands
a e defined a 340, 407 and 490 cm1. These
bands can be a ibu ed o some o he 15 ib a-
ional modes o he monoclinic phase o Z O2[30].
By annealing a T6773 K, he bands become
sligh ly sha pe and inc ease in in ensi y. This
endency is e en clea e a e annealing TP1223
K, while some new bands cen ed a 258, 460 and
570 cm1de elop in he spec um. These bands
can be also assigned o some o he 15 ib a ional
modes o he monoclinic phase o Z O2[30]. The
inc ease in in ensi y a TP1073K, he de elop-
men o new bands and he smalle wid h o he
obse ed bands abo e his empe a u e a e ac s
which a e consis en wi h he obse ed inc ease in
he c ys allini y o he monoclinic phase. This
endency can be also deduced om he dec ease o
Table 1
No malised in ensi y, e e ed o mos in ense peak o each phase and FWHM (in b acke s) o he mos significan peaks appea ing in
XRD diag ams o Fig. 2 o (Oþ
2)-Z O2samples a e indica ed annealing ea men s
Tempe a u e
Monoclinic Cubic/ e agonal
(1 1 0) (1 1 1) (1 1 1) (1 1 1) (2 2 0) (3 1 1)
300 K 18 (0.98) 18 (0.90) 100 (0.82) 100 (0.92) – –
573 K 19 (0.85) 45 (0.83) 100 (0.82) 100 (0.88) – –
773 K 21 (0.75) 58 (0.75) 100 (0.62) 100 (0.81) – –
1073 K 14 (0.72) 58 (0.57) 100 (0.39) 100 (0.40) – –
1223 K 18 (0.32) 21 (0.32) 100 (0.26) – – –
1323 K 25 (0.25) 63 (0.29) 100 (0.23) – – –
Single c ys al 25 100 70 100 50 20
338 J.P. Holgado e al. / Nucl. Ins . and Me h. in Phys. Res. B 194 (2002) 333–345
he FWHM o he peaks o he XRD diag ams
p esen ed in Fig. 2 (c . Table 1).
Fig. 5 shows he FTIR spec a co esponding o
a(O
þ
2þA þ)-Z O2sample subjec ed o diffe en
annealing ea men s. The as p epa ed sample
p esen s only a wide s uc u e wi h a maximum a
399 cm1. A e annealing a T6773 K, his
s uc u e becomes sligh ly sha pe and wo max-
ima can be obse ed a 343 and 434 cm1. To ou
knowledge ypical equencies o he ans e se
ib a ional modes o he cubic o e agonal pha-
ses o pu e Z O2a e no epo ed in li e a u e.
The e o e, compa ison is made wi h he ib a-
ional equencies o he cubic and e agonal
phases o Y ia-s abilised Z O2[31] epo ed in
Table 3. Assuming ha he p esence o y ia
migh p oduce some shi s in he posi ion o
bands, he spec a in Fig. 5 a e annealing a
TP573 K could be consis en wi h he o ma ion
o he e agonal phase. By con as , he b oad
band a 399 cm1 ound in he as p epa ed
sample, could be a ibu ed o a badly o de ed
cubic and/o e agonal phase. The b oad shapes
o all hese spec a make i difficul o disca d some
mino i y con ibu ion o a cubic phase a e an-
nealing a 573 o 773 K. The FTIR spec a o he
(Oþ
2þA þ)-Z O2samples annealed a TP1073 K
unde go d as ic changes. The shape o spec a is
be e defined, and shows bands cen ed a 330,
405 and 490 cm1. The posi ion o hese new bands
is simila o hose ha we e asc ibed o he
monoclinic phase o zi conia obse ed in he (Oþ
2)-
Z O2samples. Howe e , he supe posi ion o he
b oad IR s uc u e o he e agonal phase canno
be disca ded in hese spec a. I is in e es ing ha
no clea e idence o he p esence o he monoclinic
phase can be deduced om he XRD pa e n only
o he (Oþ
2þA þ)-Z O2sample annealed a his
empe a u e (c . Fig. 2). The diffe en long ange
o de sensi i i y o XRD and IR is likely he ea-
son o he diffe en in o ma ion p o ided by hese
wo echniques and indica e he ad an age o using
bo h me hods o a p ope e alua ion o he
s uc u e o some hin films. A e annealing a
T¼1323 K, he bands inc ease in in ensi y and
become be e defined, while some o he bands a
258, 340, 407, 460, 490 and 570 cm1become
also isible. A his final empe a u e, he spec um
is almos iden ical o ha ob ained o he (Oþ
2)-
Z O2sample annealed a he same empe a u e.
3.3. Posi on annihila ion expe imen s
The S-pa ame e e sus implan a ion ene gy in
he as p epa ed samples o (Oþ
2þA þ)-Z O2and
(Oþ
2)-Z O2se ies is plo ed in Fig. 6(a). Bo h
samples p esen almos iden ical a ia ion o his
Fig. 3. XRD pa e ns o (Oþ
2þA þ)-Z O2 hin film o he as
p epa ed samples and a e annealing ea men s a indica ed
empe a u es. The pa e ns o he mos in ense peaks o
monoclinic (bo om), cubic ( op, ull line) and e agonal ( op,
dashed line) phases o zi conia a e included o compa ison.
J.P. Holgado e al. / Nucl. Ins . and Me h. in Phys. Res. B 194 (2002) 333–345 339
pa ame e , indica ing ha he ac ion o open
olume in he samples is e y simila . By con as ,
he a ia ion o he W-pa ame e , p esen ed in
Fig. 6(b), shows some diffe ences be ween he as
p epa ed samples o (Oþ
2þA þ)-Z O2and (Oþ
2)-
Z O2. In p inciple, his change can be asc ibed o
he posi on annihila ion in he icini y o a gon
ions, as hey a e hea ie han oxygen ions and,
acco dingly, posi on annihila ion wi h i s co e
elec ons would be enhanced.
Fig. 4. FTIR spec a o he (Oþ
2)-Z O2 hin film o he as
p epa ed sample and hose ob ained a e annealing ea men s
a indica ed empe a u es.
Fig. 5. FTIR spec a o he (A þþOþ
2)-Z O2 hin film o he
as p epa ed sample and hose ob ained a e annealing ea -
men s a indica ed empe a u es.
Table 2
No malised in ensi y, e e ed o mos in ense peak o each phase and FWHM (in b acke s) o he mos significan peaks appea ing in
XRD diag ams o Fig. 3 o (A þþOþ
2)-Z O2samples a e indica ed annealing ea men s
Tempe a u e
Monoclinic Cubic/ e agonal
(1 1 0) (1 1 1) (1 1 1) (1 1 1) (2 2 0) (3 1 1)
300K–––––100(2.56)
573K–––––100(2.56)
773K–––––100(2.10)
1073 K –––––100(1.22)
1223 K 18 (0.29) 21 (0.32) 100 (0.26) – – –
1323 K 25 (0.23) 64 (0.29) 100 (0.23) – – –
Single c ys al 25 100 70 100 50 20
340 J.P. Holgado e al. / Nucl. Ins . and Me h. in Phys. Res. B 194 (2002) 333–345
Al hough he a ia ion o Sand Wpa ame e s
eflec s he p ope ies o he samples, a simul a-
neous ep esen a ion o hese wo pa ame e s in
S–W plo is usually p e e ed o a clea e desc ip-
ion o he e olu ion o he hin film p ope ies.
Fig. 7 p esen s he S–W map o he as p epa ed
(Oþ
2þA þ)-Z O2and (Oþ
2)-Z O2samples. In his
kind o plo s, in o ma ion is ob ained o he di -
e en laye s o which he sample is composed. In
he cu en s udy a h ee-laye sys em (su ace/
zi conia laye /silicon subs a e) was applied. As
expec ed, he S–W clus e poin s o he su ace and
he silicon subs a e a e iden ical in bo h samples
bu diffe en in hose o he zi conia laye . Thus,
changes in he clus e poin s o he zi conia laye
will eflec changes in he s uc u e o he film. The
a ia ion o he fi ed S–W poin s co esponding
o he zi conia laye o samples o (Oþ
2þA þ)-
Z O2and (Oþ
2)-Z O2a e annealing ea men s a
diffe en empe a u es is shown in Fig. 8. In Fig. 9
he fi ed Sand Wpa ame e s o he zi conia laye
a e plo ed independen ly e sus he annealing
empe a u e. In bo h figu es o he diffe en se s
o samples wo annealing s ages can be conside ed:
annealing om oom empe a u e o 773 K and
annealing abo e ha empe a u e. In he fi s case,
he S–W cha ac e is ic poin s mo e o highe S
alues while he Wpa ame e dec eases. Changes
in he posi on diffusion leng h we e also obse ed.
In ac , o he (Oþ
2)-Z O2samples, he posi on
diffusion leng h inc eases om 7.5 nm in he as
p epa ed sample, o 50 nm a e annealing a 773
K. Fo he as p epa ed (Oþ
2þA þ)-Z O2sample a
sho e posi on diffusion leng h was measu ed
(3 nm) and i emains sho e a e annealing a
Table 3
Some o he IR ib a ional modes o e agonal and Y ia
s abilised cubic Z O2( aken om [30])
Phase mT(cm1)
Te agonal 467
339
Y ia-s abilised cubic 358
Fig. 6. Va ia ion e sus ene gy o implan a ion in he as p e-
pa ed sample o (Oþ
2þA þ)-Z O2and (Oþ
2)-Z O2 hin films (a)
o he S-pa ame e (b) o he W-pa ame e . The lines indica e
he fi ed alues ob ained om VEPFIT.
Fig. 7. S–W plo o he as p epa ed (Oþ
2þA þ)-Z O2and
(Oþ
2)-Z O2as p epa ed, indica ing he h ee-laye sys em (su -
ace/zi conia laye /silicon subs a e). The a ows indica e he
posi on implan a ion dep h.
J.P. Holgado e al. / Nucl. Ins . and Me h. in Phys. Res. B 194 (2002) 333–345 341