synthesis of niobium doped zinc borosilicate glass …• transparent nb doped zbs glasses and glass...
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SYNTHESIS OF NIOBIUM DOPED ZINC BOROSILICATE GLASS-CERAMICS
N. Fernandes*, A. Lopes, M. Lima, J.P. Veiga, R. Monteiro**
Structural Materials, *n.fernandes@outlook.pt; **rcm@fct.unl.pt
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Summary
• Objectives
• Materials and methods
• Results
• Conclusions
Nuno Fernandes - Jornadas do CENIMAT
23-06-2014 2
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Objectives
• Synthesis of the glasses Nb-ZBS
• Study of the effect of Nb2O5 addition:
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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glass transition and crystallization temperatures
crystaline phase formation
microstructure
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Main applications
• Transparent Nb doped ZBS glasses and glass
ceramics have photoluminescent behaviour.
• Glass-ceramics based on Nb dopped ZBS have
interesting dielectric characteristics.
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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Materials and Methods
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Mixing the reagents
Glass characterization
Name %mol SiO2 %mol B2O3 %mol ZnO
1S 10 30 60
2S 20 20 60
Name %mol Nb2O5
1S-0 0
1S-2.5 2.5
1S-5 5
1S-7.5 7.5
1S-10 10
Name %mol Nb2O5
2S-0 0
2S-2.5 2.5
2S-5 5
2S-7.5 7.5
2S-10 10
Melting Vel. (ºC/min) Temp. (ºC) Time (min)
10 1350 120
Pouring and annealing
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Materials and Methods
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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Glass characterization
XRD
DSC
SEM
Glass-ceramics synthesis
Glass-ceramics characterization
XRD
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Results – XRD of glasses
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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10 20 30 40 50 60
2
Representative XRD patterns of the glasses
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Results – DSC of glasses
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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endo
450 500 550 600 650 700 750 800 850 900
Temperature (ºC)
1S - 10
1S - 2.5
1S - 5
1S - 0
1S - 7.5exo
950
554
548
545
541
538
606
606
606
606
606
648
648
648
648
648
742
742
723
706
689
937
930
933
933
932
0,0 2,5 5,0 7,5 10,0
530
540
550
560
570
T
g (
oC
)
mol% Nb2O
5
0,0 2,5 5,0 7,5 10,0
580
590
600
610
620
630T
c (o
C)
mol% Nb2O
5
0,0 2,5 5,0 7,5 10,0
630
640
650
660
670
Tp
1 (
oC
)
mol% Nb2O
5
0,0 2,5 5,0 7,5 10,0
690
700
710
720
730
740
750T
p2
(oC
)
mol% Nb2O
5
0,0 2,5 5,0 7,5 10,0
900
910
920
930
940
950T
m (
oC
)
mol% Nb2O
5
Series 1S
-
endo
450 500 550 600 650 700 750 800 850 900
Temperature (ºC)
exo
2S - 0
2S - 2.5
2S - 5
2S - 7.5
2S - 10
Results – DSC of glasses
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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566
556
550
546
542
649
641
636
680
672
667
765
763
736
725
710
820
820
820
820
820
0,0 2,5 5,0 7,5 10,0
530
540
550
560
570
580T
g (
oC
)
mol% Nb2O
5
0,0 2,5 5,0 7,5 10,0
620
630
640
650
660
Tc
(oC
)
mol% Nb2O
5
0,0 2,5 5,0 7,5 10,0
650
660
670
680
690
700T
p1
(oC
)
mol% Nb2O
5
0,0 2,5 5,0 7,5 10,0
710
720
730
740
750
760
770T
p2
(oC
)
mol% Nb2O
5
0,0 2,5 5,0 7,5 10,0
740
760
780
800
820
840
860
880
900
Tm
(ºC
)
mol% Nb2O
5
Series 2S
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Results – XRD of glass-ceramics
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10 20 30 40 50 60
ZnNb2O
6
2
1S-5
620ºC/1h
680ºC/1h
10 20 30 40 50 60
Zn3B
2O
6
2
620ºC/1h
680ºC/1h
1S-0
10 20 30 40 50 60
ZnNb2O
6
2
1S-10
620ºC/1h
680ºC/1h
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Results – XRD of glass-ceramics
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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10 20 30 40 50 60
Zn3B
2O
6
2
620ºC/1h
680ºC/1h
1S-0
10 20 30 40 50 60
Zn3B
2O
6
2
620ºC/1h
680ºC/1h
1S-0
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Results – XRD of glass-ceramics
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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10 20 30 40 50 60
ZnNb2O
6
2
1S-5
620ºC/1h
680ºC/1h
10 20 30 40 50 60
Zn3B
2O
6
2
620ºC/1h
680ºC/1h
1S-0
10 20 30 40 50 60
ZnNb2O
6
2
1S-10
620ºC/1h
680ºC/1h
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Results – XRD of glass-ceramics
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
13
10 20 30 40 50 60
ZnNb2O
6
2
1S-5
620ºC/1h
680ºC/1h
10 20 30 40 50 60
ZnNb2O
6
2
1S-5
620ºC/1h
680ºC/1h
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Results – XRD of glass-ceramics
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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10 20 30 40 50 60
ZnNb2O
6
2
1S-5
620ºC/1h
680ºC/1h
10 20 30 40 50 60
Zn3B
2O
6
2
620ºC/1h
680ºC/1h
1S-0
10 20 30 40 50 60
ZnNb2O
6
2
1S-10
620ºC/1h
680ºC/1h
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Results – XRD of glass-ceramics
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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10 20 30 40 50 60
ZnNb2O
6
2
1S-10
620ºC/1h
680ºC/1h
10 20 30 40 50 60
ZnNb2O
6
2
1S-10
620ºC/1h
680ºC/1h
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Results – phase formation
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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%mol Nb2O5 620 ºC 680ºC
0 - Zn3B2O6
5 ZnNb2O6 ZnNb2O6
10 ZnNb2O6 ZnNb2O6
Nb2O5
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Results – XRD of glass-ceramics
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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10 20 30 40 50 60
2
ZnNb2O
6
Zn3B
2O
6
2S-10
765ºC/1h
712ºC/1h
690ºC/1h
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Results – phase formation
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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Temp. (ºC) Phase
690 ZnNb2O6
712 ZnNb2O6/Zn3B2O6
765 ZnNb2O6/Zn3B2O6
Temperature
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Results – SEM of glass-ceramics
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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690ºC/1h 712ºC/1h
765ºC/1h
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Conclusions
Nuno Fernandes - Jornadas do CENIMAT 23-06-2014
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• The Nb2O5 addition causes:
decreasing of glass transition;
decreasing of crystallization temperatures;
formation of Zinc Niobate (ZnNb2O6) as the predominant phase
and Zinc Borate (Zn3B2O6) as secondary phase;
• In order to obtain nanostructured glass-ceramics
Nb2O5 addition should be
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Nuno Fernandes Jornadas do CENIMAT 23-06-2014
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Thank you.
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