ࡱ> 796'` bjbjLULU ..?.?  \! *  $"hz$!O O O !! O F O   lPҴ 4,!0\! H% H% H% 2L~6 ,o222!! 222\!O O O O $ The influence of La2O3 on sol-gel derived mullite densification behavior V. Mandic, E. Tkalcec, S. Kurajica University of Zagreb, Faculty of Chemical Engineering and Technology, 19 Marulicev trg, Zagreb, Croatia Abstract Monophasic mullite (3Al2O32SiO2) samples doped with 3.66, 7.10 and 10.29 mass% of La2O3, were prepared by a sol-gel process. Prepared gels were dried, grinded, pressed into pellets and sintered at temperatures from 1100-1600 C for 4 h. Phase formation and densification behavior has been investigated as a function of the La2O3 content and sintering temperature. Mullite thermal evolution was analyzed by Differential Thermal and Thermogravimetric Analysis (DTA/TGA) and X-ray diffraction (XRD). The density of the sintered ceramics bodies was measured using Archimedes method. With increasing lanthanum content, the DTA peak of mullite crystallization at about 980 C decreased in intensity, while the mullite crystallization was shifted to higher temperatures. Neither La2O3 nor La related compounds were detected by the XRD analysis for all doping levels, but beside mullite (-alumina was determined. The intensity of (-alumina diffraction peaks increased with the La2O3 doping level. The mullite unit cell parameters suggest predominant incorporation of La2O3 in the glassy phase, which quantity increased with the doping level. Keywords Mullite, lanthanum, sol-gel, density Hn     & / 6 7 8 9 ' ( ) * & 5 > G y B Q R | }    R \ hE jahHOhkzhkz hkz_HThHOhkzH*_HThHOhkz_HT hHOhkzhHOhkz5H*\hHOhkz5\<IJmn % Q R [ \  $@&a$gdkz$a$gdkz 7$8$H$`gdkz 7$8$H$gdkzgdkz@&gdkz ,1h. A!"#$% @`@ kzNormalCJ_HaJmH sH tH DA@D Default Paragraph FontRi@R  Table Normal4 l4a (k@(No ListIJmn%QR[\@0@0@0@0J@0J@0J@0@0@0@0@0@0@0@0@0I00%QR[\K00!K00K00K000t}00MK p00    OLE_LINK10<\=>\?\@n|x=*urn:schemas-microsoft-com:office:smarttags PlaceName=*urn:schemas-microsoft-com:office:smarttags PlaceTypeB*urn:schemas-microsoft-com:office:smarttagscountry-region9*urn:schemas-microsoft-com:office:smarttagsplace8*urn:schemas-microsoft-com:office:smarttagsCity tMSX_R/ ?~B~G9sYz=QG\Kr`+B8= x}yUbkaQ6?M0O+tP^i f)1bch"s5Mf;x,|6! $exv! 3 H w & 3 7 A L su z {    yU Z rg /  _% %, /O i 'ITV]h o| OHQZJ~ZAuzd}$;B +*LLMQW`g_u@Tfjdv!C2N:C.|^K7;~Vmse,M_zjmS|!7>jCIyl3W=E*Ko{Z;d :m g u!AdDTJK)MR}[bj{ UXf( , #0 `B w w } '!j,!k,!bI![!n!:t!"`#","Q"\\" ^"g"Bu"#p#z#J$ $*$5$=N$9%ZM%h%&8.&+'F*';'/h'er'%(!0(>(le(m( ) *)R2)4) A)H)!*K1*E*K*a*"&+0+>_+,z,K,(,R+,8,:A,HM,_\,f,j,n, -a--rL-Ld-jy-.].?&.<.z.//~\/a/ad/e/k/k/)0D01(1ZU17Y1^1c112 2DD2xY2IZ2[21b2ok23 3{'3G,3h33`39b3n3_4Z455>5O5P5e5hj56.6/6Y26^=6j7s7Zw7[8`8e8l8r8w89 9L99a9Jb9x9:f:@:C:}I:+J:5P:\]:d:e:|:h;;#;:b;d;{;" <K_<a<Lz<8|<}<O=)=/=6=G=H=Cp=Ty=>0?[!?0?&@ AAQA?xApxA B BBCCj%C1CECD?D`DE1E 2Es:E&FEFF2F8FOFOXFcFJ~FpGTLGs^G{uG"GH!H&HEH_HdHkH7uHwHN}H= I#I9)IC7I;ICITHI\I1`IJkI8vI`J7'J.JXJ]J=vJLL 2L`L\\B\]]]!]#']|:]F]LJ]LW]\]^( ^x^^$^1^[@^K^_Z^a^Qr^C8_E_`_]w_`Xk`a3aaD aGapKaza7|a=~aqbJcb|b`cFc&c1c;cKcvcVdd;dQ,de>3e\eBlepef'0f(Ef^fjfmffg=gPgeghugUh0hV>h1\hxh|h ir1i@i,j8jsj }j, k4.l`Ilnlql?mRmimjmlmCum' nnn!n'nJn7Xn&o;o;o>oKo5Voszo pEpBq]qGqHq4Jq0hqtr r'r6-r6rGr5s#As IsSsVswsCtt!t";t?t u u""uDwuexu vv$v.vSDruP-W8yDLgT^fr8&*A*2:XkY]~5pC%H]\4rWcth+#FJxjQoo  oY $9+<}TV-ACXlD1*F.LXHYA\_10[9FP0j*l!'0~q`)CSHKkNxQ&;=FoWkp #7x a4&JQ\=z67Ip~E9@VegSKg 80Rpt}"/8L<XNqTu c4ip1wA[4P Sx PM/EKOTx[ 1:6\3mFt9-3CzwEJW28}<I0K$,MSf +CDM^n*,T.2K +G8VWuy>S]Dv|: #'d@EVgliE i$':?Act?v<8 A7|h%+:@mz ;%D{(78:OV)(,s/=H`c7&fA)Cw~c/'?5]CRDbchv4 "?-U2P6?JqE{&!.6l=Cn}u445;AGG&KRj= =FYia!2B'RlP]bEik02;P>AO7;#../l6-_Agipx|&G[^d]{U~BJ-mmtHvY`">Im"8|:fmBh.04TB],cz fy d5K? W:j]"7<Bu? h1HC[fkpTx'MabUbb/ ;.I[ i0IsIU@[f#vOK pZ5,EU`ipy>(+6FY#ZZ36>t)DMVU}\nl 6PVa_6m30E_Od a+nBvss .h1RSb>@pFDlv9xNy UMZ] bm&W`s9NZcg%NJQ^jD,1/l3gZRUx$|Xo%[<Hg.rss Q C#'&3UA{Ta\d .f0\8IVd <fQN c9g=G\`ND%=RhbhlN"6f9 AFY6)7CJSfkL$;QC 4<*HP'df={FT7FGJ8Laol~%F5O_&0<AJkp qFX:h; ;(i_oy}~36OAJGs-G]^tl!Tw-z'/nKZg{!+1^kqs K ]^%.+H_@q=CxMfsy7=\BE|_x!B%Cl^xi}Nlr&zd{/?a(H6TrWAqmnbEn`nuCnY=o}$5i-nx{a%+C-Giku8xA`rLO~QSXEr%(AH +$,?djfHR[\s@I4?HHP@UnknownGz Times New Roman5Symbol3& z Arial"q;f;f  r4d 2qHX)?kz2HThe influence of La2O3 on sol-gel derived mullite densification behaviorVilkoVilkoOh+'0 0 @L l x LThe influence of La2O3 on sol-gel derived mullite densification behaviorVilkoNormalVilko1Microsoft Office Word@F#@Y(Ҵ@LҴ՜.+,04 hp  FKIT ' IThe influence of La2O3 on sol-gel derived mullite densification behavior Title  !"#$%'()*+,-/0123458Root Entry FsPҴ:Data  1TableH%WordDocument.SummaryInformation(&DocumentSummaryInformation8.CompObjq  FMicrosoft Office Word Document MSWordDocWord.Document.89q