Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
In luence o ho compac ion on mic os uc u e and magne ic
p ope ies o mechanically alloyed Fe(Co)-based amo phous
composi ions
J.J. Ipus1, J.M. Bo ego1, J.S. Blázquez1, M. S oica2,3, V. F anco1, A. Conde1
1 Depa amen o de Física de la Ma e ia Condensada, ICMSE-CSIC, Uni e sidad de Se illa, P.O. Box 1065,
41080, Se illa, Spain
2 IFW D esden, Ins i u e o Complex Ma e ials, D-01069, D esde, Ge many
3 Poli ehnica Uni e si y Timisoa a, 300006, Timisoa a, Romania
Abs ac
Amo phous Fe75Nb10B15 and (Fe70Co30)75Nb10B15 alloys we e p epa ed by mechanical
alloying om he elemen al cons i uen s and ho compac ed a di e en empe a u es
wi hin he supe cooled liquid egion. A e compac ion, he mic os uc u e s udied by X-
ay di ac ion shows an inc ease in he c ys alline ac ion o bo h composi ions.
Magne ic p ope ies and magne ic en opy change o compac ed samples o he Co- ee
alloy we e enhanced wi h espec o he powde sample, meanwhile, a de e io a ion in
hese p ope ies was obse ed o he Co con aining alloy a e compac ion. Bo h changes
could be asc ibed o an en ichmen in bo on in he amo phous phase.
Keywo ds: Amo phous and nanoc ys alline alloys, Mechanical alloying, Ho compac ion,
Magne ocalo ic e ec
Co esponding au ho : Ja ie S. Blázquez
e-mail: [email p o ec ed]
Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
In oduc ion
Nanoc ys alline and/o amo phous alloys ha e ecei ed la ge a en ion om he
scien i ic communi y in he las yea s due o hei a ac i e physical p ope ies
(mechanical, magne ic, e c), Pa icula ly, Hi pe m ype alloys [
1
] we e de eloped in 1998
o ex end he good so magne ic p ope ies p esen ed by Nanope m ype alloys [
2
]
de eloped in he 80’s o highe empe a u es, as he Co addi ion inc eases he magne ic
momen and he Cu ie empe a u e o bo h he amo phous and he c ys alline phases [
3
].
These sys ems ha e been commonly p epa ed by apid quenching echniques.
Howe e , mechanical alloying has become an impo an ool in ma e ials science as an
al e na i e ou e o di ec ly p epa e hese amo phous and nanoc ys alline mic os uc u es
in a wide composi ional ange [
4
]. Th ough his echnique, s a ing om a mix u e o
pu e elemen s o p ealloyed ma e ials, i is possible o p ocess easily and economically a
la ge amoun o powde , which is an ad an age om he comme cial applica ions poin
o iew. Fo example, al hough Co-based bulk amo phous samples ha e been p oduced
by apid solidi ica ion echniques such as coppe mold cas ing [
5
,
6
,
7
], bulk samples wi h
shapes and dimensions ha canno be ob ained by di ec cas ing ha e been success ully
p oduced by powde compac ion [
8
,
9
].
In ac , o ob ain bulk amo phous and/o nanoc ys alline samples in o de o co e
p ac ical needs, powde should be compac ed a e milling. Compac ion o amo phous
powde s in o a bulk sample p ese ing he ini ial mic os uc u e is a p ima y equi emen
bu di icul o pe o m. P essing a oom empe a u e usually leads o mechanical
deg ada ion o he compac s and high empe a u e compac ion is needed o ob ain good
in e pa icle binding. The use o a binding ma e ial enhances he mechanical s abili y o
he compac bu gene ally de e io a es i s magne ic p ope ies, as he amoun o magne ic
ma e ial is educed. I is wo h no ing ha applying high empe a u es du ing compac ion
could lead o an undesi able coa sening o he c ys als and e en c ys alliza ion o he
amo phous phase.
In his wo k, wo amo phous Fe(Co)NbB alloys a e p epa ed by mechanical
alloying. Bulk samples we e ob ained by ho p essing wi hin he supe cooled liquid
egion wi hou he use o any binding ma e ial. Mic os uc u e and magne ic p ope ies
as a unc ion o he compac ion empe a u e a e s udied and compa ed o hose o he as-
milled powde s.
Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
Expe imen al
Amo phous (Fe1-XCoX)75Nb10B15 (X=0, 0.30) alloys we e p epa ed ia
mechanical alloying s a ing om pu e c ys alline Fe, Nb and Co and in e me allic FeB
powde s in o de o enhance he inco po a ion o ha d bo on in o he ma ix [
10
]. Milling
was pe o med in a plane a y mill F i sch Pul e ise e 4 Va io, wi h s eel balls (10 mm
diame e ) and ha dened s eel ials (250 cm3), ini ial powde mass o 30 g and a ball o
powde a io o 10:1. The o a ional speed o he disc which suppo s he ials was 350
pm and ha o he ials was 700 pm in opposi e di ec ion. Powde samples we e aken
ou o s udy hei mic os uc u e, he mal s abili y and magne ic p ope ies a e 20 and
40 h milling. Disk-shaped samples 10 mm diame e and 4 mm hick we e p epa ed by
compac ion o powde s using an uniaxial ho p ess unde a acuum o 10-3 Pa. The
powde was hea ed a 0.67 K s-1 up o he consolida ion empe a u e, compac ed unde a
p essu e o 700 MPa o 1.5 min and hen cooled down o oom empe a u e using A
low. Densi y o he compac ed samples, ob ained om A chimedes me hod, shows, o
(Fe0.7Co0.3)75Nb10B15 alloy, an inc ease om 5.30.4 g/cm3 o he sample compac ed a
753 K o 6.90.5 g/cm3 o sample compac ed a highe empe a u es. In he case o he
Co- ee alloy, densi y inc eases om 6.10.4 g/cm3 o he sample compac ed a 773 K
o 6.90.5 g/cm3 o sample compac ed a highe empe a u es. This indica es abou 90
% o he expec ed densi y o a bulk amo phous sample o hese composi ions.
Mic os uc u al cha ac e iza ion was s udied by X- ay di ac ion using Cu-Kα
adia ion in a B uke D8I di ac ome e and scanning elec on mic oscopy using a Zeiss
Au iga C ossbeam Focused Ion Beam (FIB)-Scanning Elec on Mic oscopy (SEM). SEM
images we e aken on in si u polished su aces using Ga ion beam in FIB mode. The mal
cha ac e iza ion o he samples was s udied by di e en ial scanning calo ime y (DSC)
using a Pe kin Elme DSC7 a a hea ing a e o 20 K/min in a con inuous A low.
Magne ic p ope ies we e s udied using a Lakesho e 7407 ib a ing sample magne ome e
wi h a maximum applied magne ic ield o 1.5 T. Iso he mal magne iza ion cu es we e
measu ed on pa allelepipeds o abou 1x1x3 mm in size in a empe a u e ange om 100
o 753 K wi h inc emen s o 10 K. Spon aneous speci ic magne iza ion, σ0, was ob ained
om he ex apola ion o high ield magne iza ion cu es o ze o ield. Cu ie empe a u e,
Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
TC, was calcula ed as he in lexion poin o σ0(T) cu es. Hys e esis loops as a unc ion
o empe a u e we e eco ded in a empe a u e ange o 100-753 K wi h s eps o 50 K.
Iso he mal magne ic en opy change, ΔSM, due o he applica ion o a magne ic
ield, was calcula ed by p ocessing he empe a u e and ield dependen magne iza ion
cu es using a nume ical app oach o he exp ession:
2
1
0
H
M
H
H
M
S dH
T



 



, (1)
whe e M is he magne iza ion and T he empe a u e and H1 and H2 a e he minimum and
maximum applied ields. The pa ial de i a i es a e eplaced by ini es di e ences and
he in eg a ion is pe o med nume ically. This p ocedu e was pe o med wi h he help o
he Magne ocalo ic E ec Analysis P og am [
11
]. The bulk samples we e cu in o small
pa allelepipeds and i s longes axis was aligned wi h he applied ield o minimize he
demagne izing ield. In he case o powde samples he una oidable demagne izing
ac o , ND, is conside ed as 1/3 [
12
] o loosely packed sphe ical samples, in o de o
co ec he iso he mal magne iza ion cu es as:
app D
H H N M
, (2)
whe e Happ is he applied magne ic ield and H is he in e nal ield. The e ige an
capaci y ep esen s a measu e o he ene gy ans e ed be ween he ho and cold
ese oi s. In his s udy he e ige an capaci y, RCFWHM, was calcula ed as he p oduc
o he peak magne ic en opy change imes he ull wid h a hal maximum o he peak.
Resul s and Discussion
The mic os uc u al e olu ion o powde samples was ollowed by XRD. Figu e
1 shows he XRD pa e ns o samples a e 20 and 40 h milling o bo h s udied
composi ions, along wi h he decon olu ion (a Gausssian p o ile o desc ibe he
amo phous halo and a Lo en zian p o ile o he nanoc ys alline α-Fe ype phase) used o
ex ac he ac ion o phases om he pa e ns when possible. I is shown ha , a e he
o ma ion o he bcc Fe-Co(NbB) supe sa u a ed solid solu ion, he de elopmen o an
amo phous phase akes place and i s ac ion inc eases as he c ys alline one dec eases.
Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
An almos comple ely amo phous ma e ial is ob ained o Fe75Nb10B15 alloy a e 20 h
milling and o he (Fe0.7Co0.3)75Nb10B15 alloy a e 40 h. DSC eco ds p esen ed in igu e
2a show he he mal s abili y o he powde samples a e 40 h o bo h composi ions.
Di e en p ocesses can be obse ed in he scans. A low empe a u es, a gas deso p ion
p ocess s a ing a ~390 K ollowed by a b oad s uc u al elaxa ion p ocess a ~500 K.
Bo h ea u es a e ypically obse ed in powde samples [
13
]. Al hough i is no ully
accep ed he exis ence o glass ansi ion o amo phous sys ems no ob ained by apid
quenching, an exo he mic ea u e is obse ed ha could be named as Tg (inse o Fig. 2a)
and es ima ed a Tg ~760 and 785 K o (Fe0.7Co0.3)75Nb10B15 and Fe75Nb10B15 alloys,
espec i ely, and he onse empe a u e o he main c ys alliza ion p ocess was measu ed
a Ton ~815 and 850 K o (Fe0.7Co0.3)75Nb10B15 and Fe75Nb10B15samples, espec i ely.
In o de o pe o m he ho compac ion o he powde samples, one o he a ge s
was o e ain he p e iously obse ed mic os uc u e o he ini ial powde . The e o e,
empe a u es close bu below he c ys alliza ion empe a u es we e selec ed o
compac ion: 753, 773 and 793 K o (Fe0.7Co0.3)75Nb10B15 alloy and 773, 793, 803 and
813 K o Fe75Nb10B15 alloy. A comp omise has been aken be ween he hea ing a e o
he ho -p ess (limi ed o 0.67 K/min) and he DSC hea ing a e needed o ge a signi ican
signal o noise a io. A ange o empe a u es has been explo ed o minimize he in luence
o he di e en a es on he conclusions de i ed.
A e compac ion, he mic os uc u e o bulk samples was examined by XRD and
he same decon olu ion p ocedu e used o he case o as-milled powde was applied o
he compac ed samples, as shown in igu e 1. La ice pa ame e does no p esen
signi ican changes wi h compac ion (a=2.8780.005 Å o bo h composi ions). All
alues a e highe han ha o pu e bcc-Fe. This ac could be explained by he in luence
o Nb a oms in o he la ice. [
14
,
15
].
A e ho compac ion, whe eas o he Fe75Nb10B15 sample XC inc eases up o
~0.10 ega dless compac ion empe a u e, o he (Fe0.7Co0.3)75Nb10B15 sample XC
con inuously inc eases wi h empe a u e, eaching ~0.16 o he sample compac ed a 793
K. This inc emen in XC is in ag eemen wi h he close p oximi y o he compac ion
empe a u e o he c ys alliza ion empe a u e in (Fe0.7Co0.3)75Nb10B15 (T =22 K) han in
Fe75Nb10B15 alloy (T =37 K).

Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
DSC scans showing he he mal s abili y o compac ed samples a e p esen ed in
igu es 2b-c. F om hese scans we can see ha he low empe a u e p ocesses, T <750 K,
obse ed in powde samples and asc ibed o mic os uc u al elaxa ion, ha e disappea ed
o all compac ed samples. Mo eo e , no impo an changes in he peak empe a u e a e
obse ed a e compac ion o Fe75Nb10B15 alloy. Fo he (Fe0.7Co0.3)75Nb10B15 alloy,
whe eas o samples compac ed a 753 and 773 K no signi ican changes a e obse ed in
he peak empe a u es, an inc ease o ~10 K is de ec ed o he sample compac ed a 793
K. This change in he c ys alliza ion empe a u e o he (Fe0.7Co0.3)75Nb10B15 alloy could
be asc ibed o a pa ial consump ion o he ans o ma ion due o c ys alliza ion o he
bcc-(FeCo) ype phase. Mo eo e , small composi ional changes in he amo phous phase
(e.g. an en ichmen in bo on con en ) du ing compac ion a he highes empe a u e could
also lead o an inc ease in he c ys alliza ion empe a u e o he FeCo-based amo phous
alloys [
16
].
Coe ci i y, HC, a oom empe a u e shows a educ ion a e compac ion om ~2
and ~4 kA/m o Fe75Nb10B15 and (Fe0.7Co0.3)75Nb10B15 powde s, espec i ely, down o
~1 kA/m o bo h composi ions. This d op in HC could be asc ibed o elaxa ion
phenomena in he samples due o annealing du ing compac ion. Spon aneous speci ic
magne iza ion alues o compac ed samples p esen di e en beha io s o each alloy.
Fo he Fe75Nb10B15 alloy a oom empe a u e a con inuous inc ease om ~46 emu/g
(powde ) up o ~54 emu/g (compac ed a 813 K) wi h compac ion empe a u e is
obse ed. Howe e , o he (Fe0.7Co0.3)75Nb10B15 alloy no impo an changes in σ0 a e
obse ed a oom empe a u e.
The empe a u e dependence o σ0 is p esen ed in igu e 3 o he di e en
samples. I is obse ed ha TC o he (Fe0.7Co0.3)75Nb10B15 alloy does no change a e
compac ion a 753 and 773 K wi h espec o he alue obse ed o he powde sample,
wi h TC =563 K. Howe e , a educ ion down o TC =533 K o he sample compac ed a
793 K is obse ed. Fo he Fe75Nb10B15 samples, TC inc eases om 320 K, o he powde
sample, up o 340 K o each compac ed sample om 773 K o 803 K, bu a smalle
inc ease (TC =330 K) is obse ed o he sample compac ed a 813 K. These ea u es could
be ela ed o composi ional changes (a be e dissolu ion o bo on) in he amo phous
ma ix du ing he compac ion. In ac , an inc ease in bo on con en in amo phous Fe-B
leads o an inc ease in TC o ~20 K/a .% B [
17
], as well as an inc ease in σ0 [
18
]. In he
case o Co-B amo phous alloys, a dec ease o ~30 K/a .% B in TC is epo ed [
19
].
Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
Figu e 4 shows he empe a u e dependence o coe ci i y o Fe75Nb10B15 sample
compac ed a 813 K. All samples exhibi a simila beha io . An ini ial inc ease o he
coe ci i y can be seen as he measu emen empe a u e eaches TC and hen a dec ease is
obse ed o highe empe a u es. The ini ial end can be explained by a supp ession o
he exchange coupling in be ween he emaining nanoc ys als as he amo phous ma ix
become pa amagne ic. Abo e he Cu ie empe a u e o he amo phous phase, he g adual
disappea ance o he dipola coupling be ween nanoc ys als causes a educ ion in
coe ci i y as hey app oach he supe pa amagne ic egime as empe a u e inc eases [
20
].
The empe a u e dependence o he magne ic en opy change, ΔSM, o a magne ic
ield change o 1 T is shown in igu e 5 o all s udied samples. I can be seen ha , a e
compac ion, a ~15 K inc ease o he peak empe a u e akes place o he Fe75Nb10B15
alloy. Fo he (Fe0.7Co0.3)75Nb10B15 alloy he peak empe a u e shows a educ ion o ~20
K only o he sample compac ed a he highes empe a u e. The peak empe a u e, Tpk,
as a unc ion o he compac ed one, Tcomp, o bo h alloys is p esen ed in igu e 6a. The
shi o he peak empe a u e o bo h alloys ag ees wi h he shi obse ed in TC and could
be asc ibed o he inc ease in B con en in he amo phous phase du ing ho empe a u e
compac ion. In ac , an inco po a ion as small as ~0.7 a .% B in he amo phous ma ix
could explain he obse ed shi s o he peak empe a u e o bo h composi ions as
epo ed in [17,18].
The e olu ion o he peak alue o ΔSM and e ige an capaci y as a unc ion o
compac ion empe a u e a e p esen ed in igu e 6 (b and c). A con inuous educ ion in he
peak alue o |ΔSM| o compac ed (Fe0.7Co0.3)75Nb10B15 samples wi h espec o he as-
milled one can be obse ed. Howe e , o he case o Fe75Nb10B15 alloy an inc ease o
~13% in he peak alue o ΔSM o compac ed samples is obse ed. The con inuous
educ ion o he (Fe0.7Co0.3)75Nb10B15 alloy a e compac ion could be asc ibed o he
p og essi e c ys alliza ion du ing ho compac ion. In he o he case, he inc ease obse ed
o he Fe75Nb10B15 samples a e compac ion can be explained by he e ec o bo on
inco po a ion in he amo phous ma ix which enhances he magne ic momen in Fe-based
amo phous alloys [10,
21
], in ag eemen wi h he inc ease o TC.
The e ige an capaci y shows wo di e en beha io s o he wo di e en
composi ions. In he case o Fe75Nb10B15 alloy his alue dec eases wi h espec o ha o
powde sample, which is ela ed o he sha pening o he ΔSM cu e due o a educ ion o
Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
he TC dis ibu ion wi h inc easing compac ion empe a u e, as no mally obse ed o
powde samples [
22
,
23
,
24
]. Fo he (Fe0.7Co0.3)75Nb10B15 alloy signi ican changes in
RC a e no ini ially obse ed bu a la ge educ ion is measu ed a e compac ion a 793
K, which can be explained by he educ ion in he peak alue o SM due o he pa ial
c ys alliza ion o his sample.
The e a e wo p ocesses which cause B en ichmen o he amo phous phase:
c ys alliza ion o he α-Fe ype phase and dissolu ion o he emnan bo on inclusions. In
he o me case, a e a 10 % c ys alliza ion he composi ion o he esidual amo phous
phase, neglec ing he p esence o B inclusions, should be (FeCo)72Nb11B17, which could
easonably accoun o he bo on en ichmen . Howe e , p e ious s udies on Fe-Z -B [
25
]
epo on he dissolu ion o bo on inclusions a e high empe a u e ea men . In o de o
conside his mechanism, SEM mic og aphs we e ob ained on c oss sec ions o
compac ed samples a e being polished using a beam o Ga ions. Figu e 7 shows hese
SEM images a he lowes and highes compac ion empe a u es o Fe75Nb10B15 (Fig. 7a
and 7b) and (Fe0.7Co0.3)75Nb10B15 alloy (7c-7d), espec i ely. B inclusions a e s ill clea ly
obse ed as da k spo s ( egions o low in e ac ion wi h elec ons due o he low a omic
numbe o B a oms) in he compac ed samples, e en a he highes compac ion
empe a u e, and no signi ican changes a e e iden wi h espec o he samples
compac ed a lowe empe a u es. Howe e , sligh bo on inco po a ion om he
inclusions, below ou esolu ion, canno be disca ded.
Conclusions
Mechanically alloyed Fe75Nb10B15 and (Fe0.70Co0.30)75Nb10B15 powde composi ions we e
ho compac ed a di e en empe a u es and he e olu ion o he mic os uc u al and
magne ic p ope ies we e s udied.
A ound 10 % c ys alline ac ion was de eloped a e compac ion wi hin he supe cooled
liquid egion o Fe75Nb10B15 samples. Fo he (Fe0.70Co0.30)75Nb10B15 samples a
con inuous inc ease up o XC ~16% was obse ed.
The magne ic p ope ies show changes wi h he compac ion empe a u e o bo h
composi ions. Small inc eases in he oom empe a u e spon aneous speci ic
magne iza ion, he Cu ie empe a u e and he peak alue o he magne ic en opy change
Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
o he Fe75Nb10B15 alloy we e obse ed. Fo he case o (Fe0.7Co0.3)75Nb10B15 alloy a
educ ion in TC and he peak alue o he magne ic en opy change was e idenced, while
σ0 is almos cons an . In bo h cases, changes in TC could be explained a e a small bo on
en ichmen o he amo phous phase du ing compac ion. C ys alliza ion o he α-Fe ype
phase can explain he enhancemen o σ0 in Fe75Nb10B15 alloy as well as i s cons an alue
in (Fe0.7Co0.3)75Nb10B15 alloy while he peak alue o |SM| dec eases.
Acknowledgemen s
This wo k was suppo ed by he Spanish Minis y o Science and Inno a ion (MICINN)
and EU FEDER (p ojec MAT2013-45165-P) and he PAI o he Regional Go e nmen
o Andalucía.
Re e ences
[
1
] M.A. Willa d, D.E. Laughlin, M.E. McHen y, D. Thoma, K. Sicka us, J.O.
C oss, V.G. Ha is, J. Appl. Phys. 84 (1998) 6773-6677.
[
2
] K. Suzuki, N. Ka aoka, A. Inoue, A. Makino, T. Ma sumo o, Ma e . T ans. JIM
31 (1990) 743-746.
[
3
] M.E. McHen y, M.A. Willa d, D.E Laughlin, P og. Ma e . Sci. 44 (1999) 291-
433.
[
4
] C. Su yana ayana, P og. Ma e . Sci. 46 (2001) 1-184.
[
5
] A.H. Tagh aei, M. S oica, K.G. P ashan h, J. Ecke , Ac a Ma e . 61 (2013)
6609-6621.
[
6
] K. Biswas, S. Ram, S. Ro h, L. Schul z, J. Ecke , J. Ma e . Sci. 41 (2006) 3445-
3450.
[
7
] A. Inoue, Ac a Ma e . 48 (2000) 279-306.
[
8
] P. Kolla , J. Bedna cik, S. Ro h , H. G ahl, J. Ecke , J. Magn. Magn. Ma e .
278 (2006) 373-378.
[
9
] J. Fueze , J. Bedna cik, P. Kolla , S.Ro h, J. Magn. Magn. Ma e . 316 (2007)
E834-E887.
[
10
] J.J. Ipus, J.S. Blázquez, C.F. Conde, J.M. Bo ego, V. F anco, S. Lozano-Pé ez,
A. Conde, In e me allics 49 (2014) 98-105.
Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
Figu e 5.
100 200 300 400
-0.6
-0.4
-0.2
0.0
Fe75Nb10B15
powde
773 K
793 K
803 K
813 K
SM (J kg-1K-1)
T (K)
400 500 600 700
-0.8
-0.6
-0.4
-0.2
0.0
(Fe70Co30)75Nb10B15
powde
753 K
773 K
793 K
SM (J kg-1K-1)
T (K)

Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
Figu e 6.
0.4
0.6
0.8
|SM
pk| (J kg-1K-1)
(b)
293 740 760 780 800 820
40
50
60
70
(c)
TComp (K)
|RCFWHM| (J kg-1)
320
340
540
570
(a)
Tpk (K)
Jou nal o Alloys and Compounds, 653 (2015) 546-551
h p://dx.doi.o g/10.1016/j.jallcom.2015.09.074
Figu e 7.