Formation and Photoluminescence from Pr-doped CaO-TiO 2 Powders Produced by Mechanical Alloying

Formation and Photoluminescence from Pr-doped CaO-TiO ₂ Powders Produced by Mechanical Alloying

Kyung-Hwa Park · Hyun-Goo Kim ^∗

Department of Physics Education, Chosun University, Gwangju 501-759, Korea (Received 7 July 2014 : revised 21 July 2014 : accepted 21 July 2014)

The preparation and the photoluminescence from the Pr

³⁺

-doped CaTiO

3

mixture produced by using a mechanochemical method were investigated by using X-ray diffractometry (XRD), scanning electron microscopy (SEM), and luminescence spectrophotometry. In the XRD experiments, a 120 min milling of the CaO-TiO

2

mixture made it possible to synthesize CaTiO

3

. The CaTiO

3

peaks ([121], [040], and [240]) were observed after milling for 150 min. The corresponding emission spectra showed an emission range with a maximum peak at 615 nm. When the molar ratio of the Pr

³⁺

concentration was 0.1 mol%, the emission intensity of the Pr

³⁺

-doped CaTiO

3

mixture was higher than it was for the other molar ratios. The intensity of the red emission from the Pr

³⁺

-doped CaTiO

3

mixture was enhanced distinctly by increasing the annealing temperature.

PACS numbers: 81.20.Ev

Keywords: Mechanical alloying, CaO-TiO

2

mixture, CaTiO

3

M

4 X ì Ķ  ¥ Œ £ ?0 n É; c 8 ýA 0 < gX c lc Ü R CaO-TiO ² :Pr ³⁺ Ä Z Ø­  o8 ý ] k ùV R Ë õ m Í ° Ë Ñ®  o° Ë Ñ — ¤V R Ë

ƒ

‘ š# Ü é s ·  ™ »g ` @¦  ^∗

›

¸‚  @ /† < Ɠ § Ó ü t o “ §¹ ¢ ¤ õ , F  g Å Ò 501-759

(2014¸   7 Z 4 7{ 9  ~ à Î6 £ §, 2014¸   7 Z 4 21{ 9  à º& ñ ‘ : r ~ à Î6 £ §, 2014¸   7 Z 4 21{ 9  > F  S X ‰& ñ )

CaO-TiO

2

: Pr

³⁺

½ + Ë$ í ì  r ´ ú ˜`  ¦ l > & h ½ + ËF KZ O `  ¦ s 6   x # Œ  © œ“ : r \ " f ] j Œ • % i Ü ¼ 9, Õ ª + þ A$ í x 9  F  g µ 1

Ï F  g : £ ¤$ í `  ¦ › ¸  l  0 AK  X-ray diffractometry (XRD), scanning electron microscopy(SEM), Õ ªo 

“

¦ luminescence spectrophotometer\  ¦ s 6   x % i  . 120ì  r x 9 a Aô  Ç ½ + Ë$ í Ó ü t  Ò'  CaTiO

³

€  [ þ t s  # QÖ ¼

&

ñ • ¸ + þ A$ í ÷ &% 3 6 £ §`  ¦ · ú ˜ à º e ” % 3 Ü ¼ 9, 150ì  r x 9 a AÙ þ ¡`  ¦  â Ä º\   H ¢ - a„  ô  Ç CaTiO

3

 r] X ‚  s  [121], [040], [240]€  \  + þ A$ í H † d`  ¦ · ú ˜ à º e ” % 3  . 300 min x 9 a Aô  Ç r « Ñ[ þ t _  F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 “ É r 615 nm \ " f þ j@ / x  ß

¼ 8 £ ¤& ñ ÷ &% 3 Ü ¼ 9, \ P % ƒo  “ : r • ¸ 7 £ x † < Ê\     7 £ x   ) a F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 s  8 £ ¤& ñ ÷ &% 3  . Pr_  0 l x • ¸ Z >

– Ð 8 £ ¤& ñ  ) a F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3   â Ä º\   H Pr`  ¦ 0.1 mol% ' ‘ Ù þ ¡`  ¦  â Ä º_  F  g µ 1 Ï F  g y © œ• ¸  © œ ( Ž 6 £ §`  ¦

· ú

˜ à º e ” % 3  .

PACS numbers: 81.20.Ev

Keywords: l > & h “   ½ + ËF K, CaO-TiO

2

½ + Ë$ í Ó ü t, CaTiO

3

∗

E-mail: [email protected]

907

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License

(http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any

medium, provided the original work is properly cited.

I. " e  ] Ø

l

> & h “   ½ + ËF K (mechanical alloying, MA) [1–4] ~ ½ ÓZ O 

“ É

r í  H à ºô  Ç   & ñ ì  r ´ ú ˜`  ¦ " é ¶   H › ¸$ í õ 
” ¸ ß ¼l _    

&

ñ x 9  q & ñ | 9  F K5 Å q ½ + ËF K 1 p x Ü ¼– Ð ½ + Ë$ í   H D h– Ðî  r l Õ ü t – Ð +

‹ Koch 1 p x [5] \  _ K  Ni 60 Nb ₄₀ F K5 Å q Ä »o _  ] j Œ •\  6 £ x 6

 

x ÷ &% 3 Ü ¼ 9, q & ñ | 9 \  › ' a ô  Ç \ P % i † < Æ& h  õ & ñ “ É r Schwarz 1 p x [6] \  _ K  ƒ  ½ ¨÷ &% 3  .

+ þ

AF  g ^ ‰ (luminescent material)  H # Œ Q : £ ¤& ñ + þ AI _  \ 



-t \  ¦ f  ¨ à º # Œ \ P 4 Ÿ ¤  
 „   l  4 Ÿ ¤  – Ð \  -t \  ¦ ~ ½ Ó Ø

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“ É

r  ü @‚   (ultraviolet, UV)s 
 & h ü @‚   % ò % i @ /• ¸ ” > r F 

t ë ß – @ / Òì  r r  F  g‚   % ò % i \  e ”  . : £ ¤ y  100¸   s  © œ

š

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

 H + þ AF  g1 p x`  ¦ Ÿ í† < Ê # Œ, cathod ray tube (CRT), X-ray  

”

 | ó ø Í, F  g “ ¦6   x  “  ˜ Ð× ¼, plasma display panel (PDP), light emitting diode (LED) 1 p x \   6   x ÷ &# Q Ä ºo  Ò q t Ö ¸ \  x 9

] X y  › ' aº  ÷ &# Q e ” Ü ¼ 9, † ¾ ÓÊ ê _ † < Æ, ˜ Ðî ß – 1 p x “  ç ß –s  & ñ

˜

Ð\  ¦ % 3 “ ¦    H — ¸Ž  H ì  r  \  V , o   Ö ¸6   x ) a  .

%

ƒ6 £ § ' p & h Ò  o LED– Ð r  Œ •K  1990¸  @ / s Ê ê ' õ AÒ  oõ  Ñ þ ˜ Ò 

o LED  © œ6   x  o÷ &€  " f ‘ : r  & h Ü ¼– Ð r  © œs  \ P o >  ÷ &

%

3 Ü ¼
  f ”  | 9 & h  > h‚  `  ¦ 0 Aô  Ç õ ] j  H í ß –& h K  e ”   H  © œI  s

 . : £ ¤ y  & h Ò  o + þ AF  g ^ ‰  H  ü @‚  Ü ¼– РÒ'  & h Ò  o t _ 

\

 -t  s  # Œ _   â Ä º˜ Ð   8 & " f Z  }“ É r ´ òÖ  ¦ _  + þ A F 

g ^ ‰\  ¦ % 3 l  B Ä º # Q§ >  .

CaTiO 3   H CaO, CaCO 3 , Ca(OH) 2 ü < TiO ² _   o½ + ËÓ ü t

`

 ¦ €  • 1650 KÜ ¼– Ð \ P % ƒo † < ÊÜ ¼– Ð+ ‹ ½ + Ë$ í ÷ &  H y © œÄ »„   [ j



b ” _  ×  æ כ ¹ô  Ç l ‘ : rÓ ü t| 9 – Ð" f \ P & h  “ ¦y Œ ™• ¸ $ † ½ Ó^ ‰– Ð æ ¼ s

 9,  Òd ” 6   xÓ  o\  Z  }“ É r  Òd ” $ í `  ¦ ° ú   H ? / o$ í Ó ü t| 9 s   [7–10]. Õ ª Q
 — ¸Ž  H “ ¦^ ‰  © œI  ì ø Í6 £ x s  topotactic Ù ¼– Ð CaTiO <sub>3</sub> ì  r ´ ú ˜`  ¦ ç  H{ 9  >  ½ + Ë$ í   H X < # Q 9¹ ¡ §“ É r e ” Ü ¼
,

\ P

% ƒo   H ¸ ú ˜   & ñ  o  ) a CaTiO 3 \  ¦ ë ß –× ¼  H X < ×  æ כ ¹ô  Ç % i ½ + É

`

 ¦ ô  Ç .

Dhoble 1 p x [11]“ É r ƒ  ™ èZ O õ  g Ë >„  l Õ ü t \  _ K  Y 2 O ₃ :Eu + þ

AF  g ^ ‰[ þ t`  ¦ ] j Œ • % i “ ¦, ¿ º l Õ ü t \  _ K  ] j Œ •  ) a Y 2 O 3 :Eu + þ AF  g ^ ‰_  F  g µ 1 Ï F  g : £ ¤$ í õ  X-ray # Œl  µ 1 Ï F  g :

£ ¤$ í `  ¦ q “ § % i  . : £ ¤ y  Perovskite   & ñ ½ ¨› ¸\  ¦ ° ú   H CaTiO 3 :Pr“ É r €  • 615 nm Â Ò   H \ " f ¹ D 2 −→ ³ H 4 _  & h  Ò 

oµ 1 Ï F  g`  ¦
 ? / 9, $ „  · ú š6   x & h Ò  o + þ AF  g ^ ‰– Ð  o† < Æ& h Ü ¼

–

Ð î ß –& ñ “ ¦ „  l „  • ¸$ í s  Ä ºÃ º  9 $ „  · ú š \ " f s 



© œ& h “   Ò  oí  H • ¸\  ¦
  · p . Yin 1 p x [12] “ É r solid-state re- action Ü ¼– Ð CaTiO ³ :Pr`  ¦ ½ + Ë$ í % i Ü ¼ 9, Chen 1 p x [13]“ É r 900 ^◦ C \ " f à ºí ß –% i  [CaTiO(C ₂ O ₄ ) ₂ · 4H ₂ O](CTO) – ÐÂ Ò '

 CaTiO ³ :Pr ³⁺ + þ AF  g ^ ‰\  ¦ ½ + Ë$ í % i  .

‘

: r ƒ  ½ ¨\ " f  H CaO ü < TiO ² (anatase)\  ¦ s 6   x # Œ planetary ball mill – Ð ½ + Ë$ í % i Ü ¼ 9, Prs  • ¸i ç  ) a CaTiO 3 _  F  g µ 1 Ï F  g : £ ¤$ í `  ¦ · ú ˜  ˜ Г ¦  ô  Ç .

II. ÷ m Ç ] M ö

CaO-TiO 2 : Pr ³⁺ ½ + ËF K ì  r ´ ú ˜ r « Ñ_  ] j Œ •`  ¦ 0 A K

 Aldrich _  Yttrium oxide(Y 2 O 3 )(FW 225.81) ü <

TiO 2 \  Pr \  ¦ 0, 0.073, 0.1, 0.2, 0.4 mol%\  ¦ ' ‘  % i  Ü

¼ 9, MA ~ ½ ÓZ O `  ¦  6   x K " f  © œ“ : r \ " f x 9 a A % i  . x 9 a A

›

¸| Ü ¼– Ѝ  H t Ø Ô ï³ o u 6   x l \ " f ^  ¦ õ  r « Ñ_  Á º> q 

20:1 s  ÷ &• ¸2 Ÿ ¤ ì  r ´ ú ˜õ  t Ø Ô ï³ o u ½ ¨ (zirconia ball, f ”  â 10 mm)\  ¦  6   x # Œ 500 rpm_   r„  5 Å q • ¸– Ð % i  . x 9  a Ar ç ß – (milling time, t ^m )“ É r 15, 30, 45, 60, 90, 120, 150, 180, 300, 420ì  r Ü ¼– Ð % i Ü ¼ 9, / å L  ô  Ç “ : r • ¸  © œ5 p x`  ¦ } Œ •l  0

AK  15ì  r x 9 a A Ê ê 15ì  r & ñ t r (   . x 9 a Aô  Ç r « э  H 600, 700, 800, 900 ^◦ C \ " f r « Ñ\     1r ç ß –õ  2r ç ß – \ P % ƒ o

 % i  .

]

j Œ •  ) a ì  r ´ ú ˜_   © œI \  ¦ › ¸  l  0 A # Œ XRD\  ¦  6   x

% i  . XRD (PANalytical, X’pert PRO MPD)  H X-‚  

"

é

¶ Ü ¼– Ð é ß –Ò  o Cu Kα‚   (λ = 1.5406 ˚ A)`  ¦  6   x % i Ü ¼ 9,

5 Å q„  · ú šõ  „  À Ӎ  H y Œ •y Œ • 40 kVü < 30 mAs % 3  . 2θ_  8

£ ¤& ñ # 3 0 A  H 10 ∼ 65 ^◦  t – Ð % i Ü ¼ 9, Å Ò 5 Å q • ¸  H 0.5 sec/0.02 step Ü ¼– Ð % i  . ì  r ´ ú ˜_  ³ ð€  + þ AI \  ¦ › ¸  l  0

AK  FE-SEM (HIT ACHI, S − 4800)`  ¦  6   x % i Ü ¼ 9, ì

 r ´ ú ˜ ³ ð€  _   o† < Æ& h  › ¸$ í `  ¦ › ¸  l  0 AK " f SEM\   Ò

‚ Ã

Ì  ) a EDX\  ¦  6   x % i  . Thermogravimetric (TG)  H { 9 

&

ñ ô  Ç 5 Å q • ¸– Ð “ : r • ¸\  ¦    or (  `  ¦ M : Å Ò# Q”   r ç ß – 1 l x î ß – r

« Ñ_  Á º>    o\  ¦ l 2 Ÿ ¤ ô  Ç  כ s  9, Differential thermal analysis (DTA)  H r « Ñ\  ¦ { 9 & ñ ô  Ç 5 Å q • ¸– Ð \ P  <  ʓ É r Í ‰ ty Œ • r

(  `  ¦ M : Õ ª “ : r • ¸ # 3 _  î ß –\ " f  H \ P & h  : £ ¤$ í _     o

\ O

  H l ï  r Ó ü t| 9 õ  r « Ñü <_  “ : r • ¸  ∆T\  ¦ “ : r • ¸_  † < Êà º

–

Ð l 2 Ÿ ¤ ô  Ç  כ Ü ¼– Ð 50 ∼ 940 ^◦ C “ : r • ¸½ ¨ç ß –\ " f \ P 5 Å q • ¸

\

 ¦ 10 ^◦ C/min – Ð 8 £ ¤& ñ % i  . Pr`  ¦ ' ‘ ô  Ç r « Ñ ì  r ´ ú ˜[ þ t _

 \ P % ƒo  “ : r • ¸ x 9  \ P % ƒo  r ç ß –Z > , Õ ªo “ ¦ t ^m \    É r î ß –

&

ñ  © œI _  F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 “ É r luminescence spectropho- tometer\  ¦  6   x # Œ › ¸  % i  .

III. + s ÇÊ Ý õ m Í À X Ø8 ý

Figure 1“ É r MA \  _ K  15, 30, 45, 60, 90, 120, 150, 180, 300, 420ì  r 1 l x î ß – x 9 a Aô  Ç Prs  • ¸i ç  ) a CaO-TiO ₂ r « Ñ ì  r

´ ú

˜_  X-‚    r] X  — ¸€ ª œ_     o\  ¦
  · p Õ ªa Ë >s  . 15ì  r x 9

a A½ + É  â Ä º\   H x ß ¼[ þ t _   © œ@ /y © œ• ¸ / å L   >  y Œ ™™ è H † d

`

 ¦ · ú ˜ à º e ” % 3 Ü ¼ 9 [14], — ¸Ž  H x ß ¼[ þ t _  ; Ÿ ¤ s  p [ j >  V , 

#

Qt €  " f x ß ¼[ þ t s  €  •ç ß –m ”  Z  }“ É r y Œ • A á ¤ Ü ¼– Ð s 1 l x † < Ê`  ¦ ^  ¦ Ã

º e ” % 3  . s ü < ° ú  “ É r ‰ & ³ © œ“ É r ^  ¦ õ  ì  r ´ ú ˜_  Ø  æ[  t – Ð   & ñ w n  _

 p [ j o 1 p x Ü ¼– Ð “  ô  Ç ½ + Ë$ í Ó ü t _  + þ A$ í õ & ñ Ü ¼– Ð Ò q ty Œ •÷ &

Fig. 1. X-ray diffraction patterns of Pr-doped CaO-TiO 2

powders by the mechanical alloying method for different milling times.

Fig. 2. SEM micrographs for Pr-doped CaO-TiO 2 pow- ders with milling times: (a) 60 min, (b) 90 min, and (c) 150 min.

9, 120ì  r x 9 a Aô  Ç ½ + Ë$ í Ó ü t _   â Ä º\   H CaTiO 3 €  [ þ t s  # Q Ö

¼ & ñ • ¸ + þ A$ í ÷ &% 3 6 £ §`  ¦ · ú ˜ à º e ” % 3 “ ¦, 150ì  r x 9 a A % i `  ¦

 â

Ä º\   H ¢ - a„  ô  Ç CaTiO ₃  r] X ‚  s  [121], [040], [240]€  

\

 + þ A$ í H † d`  ¦ · ú ˜ à º e ” % 3  .

Figure 2  H Pr s  • ¸i ç  ) a CaO-TiO 2 r « Ñ ì  r ´ ú ˜\  @ /ô  Ç SEM _  › ' a8 £ ¤   õ \  ¦ t m \    
  · p Õ ªa Ë >s  . 60ì  r x 9

a Aô  Ç  â Ä º ´ ú §“ É r ì  r ´ ú ˜[ þ t s  é # Qo ü < ° ú  “ É r — ¸€ ª œÜ ¼– Ð + þ A

$ í

÷ &% 3 Ü ¼
 90ì  r x 9 a Aô  Ç  â Ä º\   H é # Qo [ þ t“ É r & h    



W÷ &“ ¦  Œ •“ É r ó ø Í © œs 
 <  ʓ É r é # Qo [ þ t s  { 9 Â Ò Ó ü æ 5 g" f + þ A

$ í

H † d`  ¦ ^  ¦ à º e ” % 3  . 150ì  r x 9 a A\ " f  H  8¹ ¡ ¤ & h >    W

÷

&# Q q “ §& h  ç  H{ 9 ô  Ç ß ¼l _  ì  r ´ ú ˜[ þ t – Ð + þ A$ í ÷ &% 3 6 £ §`  ¦ f ” 



Œ

•½ + É Ã º e ” % 3  .

Figure 3“ É r 300 min x 9 a Aô  Ç ì  r ´ ú ˜[ þ t`  ¦ x 9 a Aô  Ç Õ ª@ /

–

Ð_  r « Ñ (CaTiO 3 ) ü < Pr`  ¦ 0.2 mol% • ¸i ç ô  Ç r « Ñ (CaTiO 3 :Pr), Õ ªo “ ¦ CaTiO ³ :Pr r « Ñ\  ¦ 600 ^◦ C, 2 h \ " f

\ P

% ƒo ô  Ç r « Ñ ì  r ´ ú ˜[ þ t`  ¦ 325 nm – Ð # Œl r &  8 £ ¤& ñ ô  Ç F  g µ

1 Ï F  g Û ¼& 7 ˜à Ô! 3 [ þ t`  ¦ q “ §ô  Ç Õ ªa Ë >s  . 300 min x 9 a Aô  Ç Õ ª

@

/– Ð_  CaTiO ³ ½ + Ë$ í Ó ü t \ " f  H  © œ“ : r \ " f 8 £ ¤& ñ ô  Ç  â Ä º µ 1 Ï F 

g Û ¼& 7 ˜à Ô! 3 s  8 £ ¤& ñ ÷ &t  · ú §€ Œ ¤Ü ¼
, Prs  • ¸i ç  ) a CaTiO 3

½

+ Ë$ í Ó ü t“ É r @ /^ ‰& h Ü ¼– Ð € ª œ  ñô  Ç µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 s  615 nm Â

Ò   H \ " f 8 £ ¤& ñ H † d`  ¦ ^  ¦ à º e ” % 3  . s  Qô  Ç µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 

“

É r Pr s  • ¸i ç  ) a CaTiO 3 ì  r ´ ú ˜_  „  + þ A& h “     É r µ 1 Ï F  g Û ¼

Fig. 3. (Color online) PL emission spectra of CaTiO ₃ , CaTiO ₃ :Pr (Pr = 0.1 mol%), and CaTiO ₃ :Pr (Pr = 0.1 mol%, 600 ^◦ C, 2 h).

Fig. 4. (Color online) PL emission spectra for Pr-doped CaTiO 3 mixtures with different temperatures.

&

7 ˜à Ô! 3  [15]õ  q “ §K " f B Ä º Ä » ô  Ç — ¸€ ª œs  + þ A$ í H † d`  ¦ ^  ¦ Ã

º e ” % 3 Ü ¼ 9, s   H Pr ³⁺ s “ : r _  „  s  ( ¹ D 2 −→ ³ H 4 ) \  @ / 6

£

x ÷ &  H  כ Ü ¼– Ð Ò q ty Œ •  ) a   [12,16]. Õ ª Q
 CaTiO ³ :Pr r 

«

Ñ\  ¦ 600 ^◦ C, 2 h \ " f \ P % ƒo  Ù þ ¡`  ¦  â Ä º\   H \ P % ƒo   t

 „  _  µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3  x ß ¼ y © œ• ¸˜ Ð  €  • 6C  Z  }“ É r F  g µ

1 Ï F  g Û ¼& 7 ˜à Ô! 3 s  8 £ ¤& ñ ÷ &% 3  . Figure 3(b)  H z  ´] j lumi- nescence spectrophotometer – Ð 8 £ ¤& ñ  ) a  ”  Ü ¼– Ð" f   © œ _

 # 3 0 A\  ¦ 400 ∼ 700 nm – Ð % i `  ¦  â Ä º µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3  x

ß ¼\  ¦ ˜ Ð# Œï  r Õ ªa Ë >s  .

Figure 4  H Pr`  ¦ • ¸i ç ô  Ç CaTiO <sub>3</sub> r « Ñ ì  r ´ ú ˜`  ¦ \ P % ƒo 

“

: r • ¸Z > – Ð y Œ •y Œ • 2r ç ß –m ”  \ P % ƒo  # Œ 8 £ ¤& ñ ô  Ç F  g µ 1 Ï F  g Û ¼& 7 ˜ à

Ô! 3 s  . 600 ^◦ C ü < 700 ^◦ C F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3  x ß ¼[ þ t“ É r q

5 p w ô  Ç y © œ• ¸\  ¦ ˜ Ð% i Ü ¼
, \ P % ƒo  “ : r • ¸ 800 ^◦ C ü < 900

◦ C  t   H \ P % ƒo  “ : r • ¸ 7 £ x † < Ê\     F  g µ 1 Ï F  g [ jl 

@

/^ ‰& h Ü ¼– Ð & f ” `  ¦ · ú ˜ à º e ” % 3  .

Fig. 5. (Color online) Pre-annealing and post-annealing PL emission spectra for CaTiO ₃ :Pr (600 ^◦ C, 2 h) mix- tures with different Pr concentrations.

Figure 5  H Pr`  ¦ ]  t 0 l x • ¸Z > – Ð • ¸i ç  ) a CaO-TiO ₂ r « Ñ ì

 r ´ ú ˜`  ¦ \ P % ƒo  „  õ  600 ^◦ C, 2 h \ " f \ P % ƒo ô  Ç r « Ñ ì  r ´ ú ˜ [

þ

t \  @ /ô  Ç F  g µ 1 Ï F  g y © œ• ¸\  ¦ q “ §ô  Ç Õ ªa Ë >s  . Pr`  ¦ 0.073, 0.1, 0.2, 0.4 mol% ' ‘ Ù þ ¡`  ¦  â Ä º 0.1 mol% ' ‘  Ù þ ¡`  ¦  â Ä

º_  µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 s  \ P % ƒo  # ŒÂ Ò\  › ' a > \ O s   © œ a % ~

>

 8 £ ¤& ñ ÷ &% 3 Ü ¼ 9, Pr`  ¦  8 ´ ú §s  ‚ à н + Éà º2 Ÿ ¤ µ 1 Ï F  g Û ¼& 7 ˜à Ô

!

3 s   8 €  • >  8 £ ¤& ñ H † d`  ¦ · ú ˜ à º e ” % 3  . x 9 a Aô  Ç Õ ª@ /– Ð _

 r « Ñ[ þ t \  @ /ô  Ç F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 • ¸ @ /^ ‰& h Ü ¼– Ð € ª œ  ñ Ù þ

¡Ü ¼
, 600 ^◦ C, 2 h 1 l x î ß – \ P % ƒo ô  Ç r « Ñ ì  r ´ ú ˜[ þ t _   â Ä º

\

  H : £ ¤ y   Å Ò Ä ºÃ ºô  Ç µ 1 Ï F  g y © œ• ¸[ þ t s  8 £ ¤& ñ H † d`  ¦ ^  ¦ à º e ” 

%

3  . Figure 5(b)\ " f ^  ¦ à º e ” 1 p w s  Pr`  ¦ 0.073 mol ' ‘ 

ô  Ç  â Ä º\  ¦ ] jü @ “ ¦  H @ /^ ‰& h Ü ¼– Ð r « Ñ_  µ 1 Ï F  g y © œ• ¸



 H \ P % ƒo  t  · ú §“ É r r « Ñ_  µ 1 Ï F  g y © œ• ¸ ˜ Ð  €  • 6C  s  © œ 7

£

x ô  Ç  כ Ü ¼– Ð 8 £ ¤& ñ ÷ &% 3  .

Figure 6“ É r Pr`  ¦ ]  t 0 l x • ¸Z > – Ð • ¸i ç ô  Ç CaTiO 3 r « Ñ ì  r

´ ú

˜`  ¦ UVÏ þ ›á Ô (UVGL-58)– Ð › ¸  (irradiation) l  „   ( Õ ªa Ë > ¢ , aA á ¤, A) õ  › ¸ ô  Ç Ê ê (Õ ªa Ë > š ¸ É rA á ¤, B) _  F  g µ 1 Ï

Fig. 6. (Color online) Photographs of CaTiO ₃ :Pr of be- fore (A) and after (B) irradiation with a UV lamp for dif- ferent Pr concentrations before annealing: (a: 0.1 mol%), (b: 0.2 mol%), (c: 0.4 mol%), and after annealing: (d:

0.1 mol%), (e: 0.2 mol%), (f: 0.4 mol%).

Fig. 7. XRD patterns of Pr-doped CaO-TiO 2 powders for milling 90 min with 1 h and 2 h at 600 ^◦ C.

F 

g y © œ• ¸\  ¦ q “ §ô  Ç  ”  s  . ¢ ¸ô  Ç  ”   Aü < B\ " f• ¸ (a:

0.1 mol%), (b: 0.2 mol%), (c: 0.4 mol%)  H \ P % ƒo   l

 „  _   ”  s “ ¦, (d: 0.1 mol%), (e: 0.2 mol%), (f: 0.4 mol%)  H \ P % ƒo  Ê ê_   ”  s  . UVÏ þ ›á Ԗ Ð › ¸  l  „  

\

  H Pr _  mol% € ª œ\  › ' a > \ O s  — ¸Ž  H r « Ñ\  µ 1 Ï F  g ‰ & ³ © œ s

 ¸ ú ˜
 
t  · ú §€ Œ ¤Ü ¼
, UVÏ þ ›á Ԗ Ð › ¸ ô  Ç Ê ê\   H — ¸

Ž

 H r « Ñ\  Ô  „“ É r y n C¾ ú ˜`  ¦ ™   F  g µ 1 Ï F  g s  ‚  " î > 
 z Œ ™`  ¦

^

 ¦ à º e ” % 3  . : £ ¤ y  UVÏ þ ›á Ԗ Ð › ¸ ô  Ç Ê ê_  r « Ñ ×  æ \ " f

•

¸ \ P % ƒo ô  Ç r « Ñ_  F  g µ 1 Ï F  g“ É r Ô  „“ É r y n Cs   Å Ò ‚  " î > 

¸ ú

˜
 z Œ ™`  ¦ ^  ¦ à º e ” % 3 Ü ¼ 9, Pr`  ¦ 0.1 mol% ' ‘ ô  Ç r « Ñ _

 F  g µ 1 Ï F  g s   © œ ‚  " î > 
 z Œ ¤“ ¦, Prs   8 ´ ú §s  ‚ à Ð

 | ¨ c à º2 Ÿ ¤ Ô  „“ É r y n C¾ ú ˜_  F  g µ 1 Ï F  g s   8 €  • > 
 z Œ ™`  ¦ ^  ¦ Ã

º e ” % 3  . s   H Fig. 5 _  F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3  / B G‚  _     o ü

<• ¸ { 9 u  % i  .

Figure 7“ É r 90 min 1 l x î ß – x 9 a Aô  Ç CaO-TiO ₂ r « Ñ ì  r ´ ú ˜

`

 ¦ 600 ^◦ C \ " f 1 hõ  2 h \ P % ƒo ô  Ç X-‚    r] X  — ¸€ ª œ_ 



  o\  ¦
  · p Õ ªa Ë >s  . q 2 Ÿ ¤ 90ì  r 1 l x î ß – x 9 a Aô  Ç CaO- TiO ₂ r « Ñ ì  r ´ ú ˜s  “ ¦ ½ + Ét  • ¸ \ P % ƒo ½ + É  â Ä º\   H — ¸

¿

º CaTiO 3 x ß ¼[ þ t s  8 £ ¤& ñ H † d`  ¦ · ú ˜ à º e ” % 3  .

IV. + s Ç Â ] Ø

CaO-TiO ₂ : Pr ³⁺ ½ + Ë$ í ì  r ´ ú ˜`  ¦ l > & h ½ + ËF KZ O `  ¦ s 6   x

# Œ  © œ“ : r \ " f ] j Œ • % i Ü ¼ 9, Õ ª + þ A$ í x 9  F  g µ 1 Ï F  g : £ ¤$ í

`

 ¦ › ¸  l  0 AK  X-ray diffractometry (XRD), scanning electron microscopy (SEM), Õ ªo “ ¦ luminescence spec- trophotometer\  ¦ s 6   x % i  . 120ì  r x 9 a Aô  Ç ½ + Ë$ í Ó ü t  Ò'  CaTiO ₃ €  [ þ t s  # QÖ ¼ & ñ • ¸ + þ A$ í ÷ &% 3 6 £ §`  ¦ ^  ¦ à º e ” % 3 Ü ¼ 9, 150ì  r x 9 a Aô  Ç ì  r ´ ú ˜_   â Ä º\   H ¢ - a„  ô  Ç CaTiO ₃  r ] X

‚  s  [121], [040], [240]€  \  + þ A$ í H † d`  ¦ · ú ˜ à º e ” % 3  .

300 min x 9 a Aô  Ç r « Ñ[ þ t _  F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 “ É r Pr ³⁺ _  „   s

( ¹ D 2 −→ ³ H 4 ) \  @ /6 £ x ÷ &  H  כ Ü ¼– Ð Ò q ty Œ •÷ &  H 615 nm \ 

"

f þ j@ / x ß ¼ 8 £ ¤& ñ ÷ &% 3 Ü ¼ 9, \ P % ƒo  “ : r • ¸ 7 £ x † < Ê\ 



 " f @ /^ ‰& h Ü ¼– Ð F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 s  † ¾ Ó © œ H † d`  ¦ · ú ˜ à º e ”

% 3  . Pr_  0 l x • ¸Z > – Ð 8 £ ¤& ñ  ) a F  g µ 1 Ï F  g Û ¼& 7 ˜à Ô! 3 “ É r Pr`  ¦ 0.1 mol% ' ‘ Ù þ ¡`  ¦  â Ä º_  F  g µ 1 Ï F  g y © œ• ¸  © œ ( Ž 6 £ §`  ¦

· ú

˜ à º e ” % 3  .

P

c p 8 ý ò k >

This study was supported by research fund from Chosun University, 2014.

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