Synthesis of Ultrafine LaAlO<TEX>$_3$</TEX> Powders with Good Sinterability by Self-Sustaining Combustion Method Using (Glycine+Urea) Fuel

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J. Korean Ceram. Soc. > Volume 36(2); 1999 > Article

Journal of the Korean Ceramic Society 1999;36(2): 203.

(Glycine+Urea) 혼합연료를 이요한 자발착화 연소반응법에 의한 우수한 소결성의 초미분체 LaAlO$_3$ 분말 합성

남희동, 최우성, 이병하, 박성

명지대학교 무기재료공학과

Synthesis of Ultrafine LaAlO$_3$ Powders with Good Sinterability by Self-Sustaining Combustion Method Using (Glycine+Urea) Fuel

ABSTRACT

LaAlO3d single phase used as the butter layer on Si wafer for YBa2Cu3O7-$delta$ superconductor application were prepared by solid state reaction method and by self-sustaining combustion process. The microstructure and crystallity of synthesiszed LaAlO3 powder studied using scanning electron microscope (SEM) and X-ray diffractometer(XRD), specific surface area and sintering characteristics fo powder were investigated by Brunauer-Emmett-Teller (BET) method and dilatometer respectively. In solid state reaction method, it is difficult to obtain LaAlO3 single phase up to 150$0^{circ}C$ period. However, in self-sustaining combustion process, it is to easy to do it only $650^{circ}C$. Based on the results of analysis of dilatometer it is easier to obtain high sintering density (98.87%) in self-sustaining combustion process than in the solid state reaction method. This reason is that the average particle size prepared by self-sustaining combustion process is nano crystal size and has high specific surface are value(56.54 $m^2$/g) compared with that by solid state reaction method. Also, LaAlO3 layer on the Si wafer has been achieved by screen printing and sintering method. Even though the sintering temperature is 130$0^{circ}C$, the phenomena of silicon out diffusion in LaAlO3/Si interphase are not observed.

Key words: Self-sustaining combustion process, Solid state reaction method, Superconductor, Buffer layer, LaAlO$_3$