초록
$Y_2Ba_1Cu_1O_5(Y211)$ 분말은 출발물질로서 $Y_2O_3(99.9%)$, $BaCO_3(99.9%)$, and CuO(99.9%) 분말을 사용하여 고상반응법과 발화합성법을 이용하여 제조하였다. $Y_2Ba_1Cu_1O_5(Y211)$ 분말에 대한 상형성과 반응속도는 열처리 온도와 반응시간에 따른 시료들을 X-선 회절분석을 이용하여 연구하였다. X-선 회절선으로부터 측정된 전화율($X_{211}$)과 반응특성으로부터 상 형성속도가 분말의 입자크기에 의해 지배되는 것을 알 수 있었다. 그리고 발화합성법으로 제조된 Y211상의 활성화에너지(${\Delta}E_a$)는 고상반응법에 의해 제조된 것의 149.46 kJ/mol과 비교할 때 136.42 kJ/mol을 나타내었다. $Y_2Ba_1Cu_1O_5$계에서의 활성화에너지 값은 발화합성법이 고상반응법보다 더욱 효율적인 방법임을 보였다.
$Y_2Ba_1Cu_1O_5(Y211)$ powders were prepared by pyrophoric synthesis method and by solid state reaction method using $Y_2O_3(99.9%)$, $BaCO_3(99.9%)$, and CuO(99.9%) powders in both of these processes. The phase formation and reaction kinetics of $Y_2Ba_1Cu_1O_5$ powders have been studied using X-ray diffraction analysis(XRD) of samples at various heat treatment temperatures and reaction time. The reaction characterization suggested that the phase formation rate is mainly controlled by the particle size of Y211 powders. The activation energy(${\Delta}E_a$) of Y211 phase formation in this pyrophoric synthesis method was found to be 136.42 kJ/mol compared with 149.46 kJ/mol for that of solid state reaction method. These results data showed that the pyrophoric synthesis method is kineticaly more efficient than the solid state reaction method in this $Y_2Ba_1Cu_1O_5$ system.