Preparation of dense La0.7Ca0.3MnO3 ceramics from freeze-dried precursors
Preparation of dense La0.7Ca0.3MnO3 ceramics from freeze-dried precursors
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冻干前驱体制备致密 La0.7Ca0.3MnO3 陶瓷
DOI：
10.1016/s0955-2219(00)00080-7
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Y. Tret’yakov
中科院分区：
文献类型：
--
作者：
O. A. Shlyakhtin;Y. Oh;Y. Tret’yakov
研究了La0.7Ca0.3MnO3前驱体的烧结性能，为制备致密（>95%）陶瓷提供了一种新的方法。通过在650°C下热分解获得的单相粉末通过超声波或机械处理进行解聚。在T=1200-1300°C下烧结解团聚的粉末数小时允许实现高达97- 98%的密度。最好的烧结性通过机械加工的粉末来证明，但是由该前体获得的陶瓷的进一步烧结导致显著的去致密化（在1300°C下高达85%）。对前体和去致密化样品的分析表明，在高温下，封闭孔隙中碳酸盐的分解是所观察到的过程的最可能原因。
Sinterability of La0.7Ca0.3MnO3precursors, obtained by the freeze-drying method, is studied in order to develop a technique for preparation of dense (>95%) ceramics for CMR measurements and sputtering applications. Single phase powders, obtained by thermal decomposition at 650°C, were subjected to deagglomeration by ultrasonic or mechanical treatment. Sintering of deagglomerated powders for several hours at T=1200–1300°C allowed to achieve densities up to 97–98%. The best sinterability is demonstrated by mechanically processed powder, but further sintering of ceramics, obtained from this precursor, results in significant dedensification (up to 85% at 1300°C). Analysis of precursors and dedensified samples shows at high temperature decomposition of carbonates in closed pores to be the most probable reason for the observed process.