: Al 2 O 3,,, PACS: Gm, Ch, fc , A1 2 O 3. ( Y 2 O 3, La 2 O 3, Yb 2 O 3, Eu 2 O 3 ),, (LED), ,, LED

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1 * (, ) ( ; ),. ;. X 1500 C W/(m K),. Y 3+ La 3+,. : Al 2 O 3,,, PACS: Gm, Ch, fc 1,., (LED),,,,, LED,., LED [1 3]. LED,,,. LED,, LED 15%,,, LED., LED. LED,,, LED [3]., A1 2 O 3,,., ( Y 2 O 3, La 2 O 3, Yb 2 O 3, Eu 2 O 3 ),,,,,, [4 7].,,,.,. 2 Al 2 O 3, Y 2 O 3, La 2 O 3, : 99.2 mol% Al 2 O mol% ; * ( : ) ( : 2010B ) ( : 2010Y1-C221). xgtang@gdut.edu.cn c 2012 Chinese Physical Society

2 Ô n Æ Acta Phys. Sin. Vol. 61, No. 20 (2012) mol% Al2 O3, 1 mol% Y2 O3, 0.2 mol% ( Ô5ÿþXÚÿÁ, 9 ÿá ò>b ÏJ; 1n 98.8 mol% Al2 O3, 1 mol% La2 O3» 5 mm, þ 2 mm, ÿá Ý 300 K. Ú 0.2 mol% ( Ï J. n ( Ï J SiO2 Ú Li2 CO3, ü«ô m '~ 1 : 1. Uì g zæoþ'?1, æ^ DÚ >b ó² >b g Ü [8]. n«u -, ^ÃY U 0, 24 h, òóz "Lç., 3 (J9?Ø ( 3.1, n«ø ã 1,ØÓ n Al2 O3 Ä>b Ó "Úà LU (PVA) þ! Ü, ²LÅ(JE 3 5 ØÓ ( ÝÚ 6 h eÿ XRD â / û ã Ì. d ã 1(a) ± w Ñ, / A12 O3 MN, ÏLéì PDF k, vk* Ù,. 3+, Ø» 13 mm, þ 3 mm.n, 2 O C, 1350 C, 1400 C, 1450 C Ú 1500 C e ( 6 h, A ØÓ ( Ý ã 1(b) (c) O, Y 3+ α- Ú La. é' 1350 C 20 MPa 9Ø ( V A12 O3 XRD û ãì, ü«, >b \ (ÏJ Al2 O3 >b. Øuy þ Y2 O3 Ú La2 O3,, vk* æ^ X û (XRD, u Cu Kα) Ù,. ùl² Y3+ ½ La3+ ²?\ A12 O3,?1 N( Û. >bl ²L ²! Óâ 1, æcõ>4. 3ØÓªÇe 0>~ê MN. ), Ï U ^Dè, Ú Ñæ^ Ú{ Û (HP 4192A.{ A12 O3 / ü MN 3 þ, L Û )?1ÿþ. Tþ Ü, ±õ{, /ª 3. ã1 9 5U^ PPMS-9 nü Ù Al3+, l ØÓ ( Ý Al2 O3 Ä>b XRD ã (a) X Al2 O3 ; (b) Y Al2 O3 ; (c) La Al2 O Ä / ü

3 2 A1 2 O 3 Y 3+, La 3+ A1 2 O C XRD. 2,,., Y 3+ A1 2 O 3., (113), Y 3+ La 3+ ( 2 ), d, Y 3+ (0.9 Å) La 3+ (1.9 Å) Al 3+ (0.5 Å) C Al 2 O 3 Y 3+, La 3+ XRD C Al 2 O 3 Y 3+, La 3+ a/å c/å V /Å 3 Al 2 O Y 3+ Al 2 O La 3+ Al 2 O XRD, ( 1). α-a1 2 O 3,, a = b.,,. A1 2 O 3 Y C, La 1450 C., Y 3+ Al 2 O C Å 3,., Y 3+ La 3+, Al 2 O 3. Al 3+, C Al 2 O 3., Al 2 O 3, 8.60 W/(m K), Y 3+, La 3+ Al 2 O 3, W/(m K),., 1350 C 20 MPa W/(m K). 2,. Li 2 CO 3 SiO 2 ( 2), Al 2 O 3 0.4%,.,,,,,, Al 2 O 3.,,,,, [9].,.,, Y 3+, 2, Y 3+ XRD Y 2 O 3, Al 2 O 3 Y 2 O 3, Y-Al-O,,, [10]. La 3+ XRD La 2 O 3. Al 2 O 3, Y 3+, La 3+,. 2 / (SiO 2 Li 2 CO 3 W m 1 K 1 ) Al 2 O wt% Al 2 O wt% Al 2 O 3 -Y 2 O wt% 1% 2.02 Al 2 O 3 -La 2 O wt% 1% 3.15,,

4 .,. 3.3 Al 2 O 3 Y 3+ La 3+, ε. ε r, 15 40, tan δ,.,, 50 C, 100 C, 150 C, 200 C, 250 C, 300 C, 350 C, 400 C, 450 C, 500 C, 550 C 600 C. 50 C 350 C,.. Z = Z + jz = 1/(jC 0 ε ω), (1), R gb C gb (grain boundary),, 4 (Z, Z ), Z. Cole-Cole [12], Z = R/{1 + AR(jω) 1 α }, (2) A, α (α = 0 ). α > /4,,. 3 4,,., ;. [13]. C 0, ε, ω(= 2πυ) C Al 2 O C C Y 3+ Al 2 O C. 4 Y 3+ Al 2 O C 3 Al 2 O C 3 4, Y,., RC [11], 3. (grain) R g C g C La 3+ Al 2 O 3.,,, C 600 C, 400 C,,, 600 C. [14]. C gb, ( )

5 , Cole-Cole,, La 3+,,, C, C gb., 400 C 600 C,,,, (Na 0.5 Bi 0.5 )TiO 3 [15].,,,,,,. 5 La 3+ Al 2 O 3 (a) ; (b) 400 C; (c) 450 C; (d) 500 C; (e) 550 C; (f) 600 C

6 , [16]., (superparaelectric), (dipolar-glass),,, [17]., Zr BaTiO 3 [18]. Y 3+ La 3+ A1 2 O 3, Y 3+ (0.9 Å) La 3+ (1.9 Å) Al 3+ (0.5 Å), Y 3+ La 3+ Al 3+.,, Al 3+, A1 2 O 3,. 4,. ; (1300 C 1500 C). Al 2 O 3 Y 3+ La 3+,. Al 2 O W/(m K), Al 2 O 3. Y 3+ La 3+ Al 3+.,, Al 3+, A1 2 O 3,. Al 2 O W/(m K), LED. [1] Svilainis L 2008 Displays [2] Kee R J, Almand B B, Blasi J M, Rosen B L, Hartmann M, Sullivan N P, Zhu H Y, Manerbino A R, Menzer S, Grover Coors W, Martin J L 2011 Appl. Thermal. Eng [3] Yin L Q, Yang L Q, Yang W Q, Guo Y S, Ma K J, Li S Z, Zhang J H 2010 Solid-State Electron [4] Peng R, Zhou H P, Ning X S, Xu W, Lin Y B 2002 J. Inorg. Mater (in Chinese) [,,,, ] [5] Mu B C, Sun X D 2002 J. Chin. Rare Earth Soc. 20 z104 (in Chinese) [, z104] [6] Yang Q H, Zeng Z J, Xu J, Su L B 2006 Acta Phys. Sin (in Chinese) [,,, ] [7] Yao Y J, Qiu T, Jiao B X, Shen C Y 2005 J. Chin. Rare Earth Soc (in Chinese) [,,, ] [8] Chen D G, Tang X G, Jia Z H, Wu J B, Xiong H F 2011 Acta Phys. Sin (in Chinese) [,,,, ] [9] Huang L P, Zhao H F, Fu X R, Dong L J 1989 J. Inorg. Mater (in Chinese) [,,, ] [10] Zhou H P, Zhou J S 1995 J. Inorg. Mater (in Chinese) [, ] [11] Ferrarelli M C, Sinclair D C, West A R, Dabkowska H A, Dabkowski A, Luke G M 2009 J. Mater. Chem [12] Sarkar S, Jana P K, Chaudhuri B K 2008 Appl. Phys. Lett [13] Cole K S, Cole R H 1941 J. Chem. Phys [14] Sinclair D C, West A R 1989 Phys. Rev. B [15] Kim J S, Choi B C, Jeong J H, Chung S T, Cho S B, Kim I W 2009 J. Kor. Phys. Soc [16] Elissalde C, Ravez J 2001 J. Mater. Chem [17] Kuang S J, Tang X G, Li L Y, Jiang Y P, Liu Q X 2009 Scripta Mater [18] Tang X G, Wang J, Wang X X, Chan H L W 2004 Solid State Commun

7 Influences of Y- and La-dopant on the thermal conductive properties and dielectric relaxation of Al 2 O 3 -based ceramics Wu Jun-Bo Tang Xin-Gui Jia Zhen-Hua Chen Dong-Ge Jiang Yan-Ping Liu Qiu-Xiang ( School of Physics and Optoelectric Engineering, Guangdong University of Technology, Guangzhou , China ) ( Received 2 November 2011; revised manuscript received 15 April 2012 ) Abstract Al 2O 3 ceramics doping with Y 3+ and La 3+ are synthesized by conventional solid state reaction method. The structures, thermal conductivities properties and the effects of sintering temperature on the electrical properties of the samples are measured. X-ray diffraction results indicate that all the ceramics are formed to be of pure solid solution when the samples are sintered at 1500 C. Thermal conductivities of Al 2O 3 ceramics reach up to 8.60 W/(m K). All the ceramics show temperature-stable dielectric characteristics. Typical dielectric relaxation behaviors are observed in Y- and La-doped Al 2O 3 ceramics, and the relaxation mechanism is also analyzed. Keywords: Al 2 O 3, ceramics, thermal conductivity, dielectric relaxation PACS: Gm, Ch, fc * Project supported by the National Natural Science Foundation of China (Grant No ), the Science and Technology Program of Guangdong Province, China (Grant No. 2010B ), and the Science and Technology Project of Guangzhou City, China (Grant No. 2010Y1- C221). xgtang@gdut.edu.cn