Crystal Growth of Superconducting Y-Ba-Cu-O by Flux Technique

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J. Korean Ceram. Soc. > Volume 26(1); 1989 > Article

Journal of the Korean Ceramic Society 1989;26(1): 59.

융제법에 의한 Y-Ba-Cu-O 초전도체의 단결정 육성

박승익, 박현민, 정수진, 박병규¹, 박병학¹

서울대학교 무기재료공학과
¹산업 과학 기술 연구소

Crystal Growth of Superconducting Y-Ba-Cu-O by Flux Technique

ABSTRACT

Single crystals of the superconducting Y-Ba-Cu oxide were grown by a flux technique. Stoichiometric mixture with excess BaO and CuOcontent was melted at 130$0^{circ}C$, followed by fast cooling to 108$0^{circ}C$ to prevent crystallizing of CuO. It was then reheated to 110$0^{circ}C$ followed by being held at this temperature to control the number of nuclei, and cooled by 5$^{circ}C$/hr to 80$0^{circ}C$. This procedure was repeated with various compositions and crystals were obtained in cavity. Molten solution was seperated to two parts : the upper part of almost CuO and the rest of different composition. Appropriate composition of flux was 30mol% BaO and 70mol% CuO due to the seperation of molten solution. Single crystals have the habit of thin plate with good developed (001) crystal face, XRD, EDAX and single crystal X-ray investigations were carried out. The grown crystals have tetragonal structure with the lattice parameters a=b=3.84$AA$, c=11.7$AA$, and the space group P4/mmm. The crystal surface were observed by SEM.