Growth and characterization of REBa2Cu3O7−δ
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- 作者：Alcione Roberto Jurelo ; Jú ; lio Flemming ; Francisco Carlos Serbena ; Cé ; lia Regina Carubelli ; Pedro Rodrigues Jr. ; Carlos Eugê ; nio Foerster ; Fabio Teixeira Dias ; Ivan Ondino de Carvalho Mass
- 关键词：A1. Characterization ; A2. Single crystal growth ; B1. Cuprates ; B2. Oxide superconducting material
- 刊名：Journal of Crystal Growth
- 出版年：2009
- 出版时间：15 June 2009
- 年：2009
- 卷：311
- 期：13
- 页码：3539-3543
- 全文大小：332 K
文摘
Single crystals of REBa2Cu3O7−δ (RE=natural mixture of Y and heavy lanthanides in the single crystals) superconductor were successfully grown using rare-earth oxides extracted from xenotime mineral, allowing an alternative and simple route for superconductor single-crystal production. The methodology to extract the rare-earth mixed oxides from the xenotime mineral has three main steps: alkaline fusion, acid lixiviation and oxalic precipitation. Large single crystals with a typical 5×5×0.03 mm3 size were obtained by using a CuO–BaO self-flux and were characterized by scanning electron microscopy (SEM), energy-dispersive electron spectroscopy, X-ray diffraction, magnetic measurements and nanoindentation. The composition of the rare-earth elements of the crystal was different from the starting mixture, possibly due to the different solubilities of the elements in the melt. The final crystal stoichiometry was RE:Ba:Cu=1:2:3. X-ray diffraction analysis showed highly oriented c-axis (c=11.716±0.002 Å). The critical temperature was determined to be around TC88–89 K after the crystals have been submitted to oxygen annealing. Hardness and elastic modulus for ab- and b(a)c-planes were 8.5±0.5 and 160±20 GPa, respectively.