| 173 | 10 | 33 |
| 下载次数 | 被引频次 | 阅读次数 |
采用化学共沉淀方法 ,以氧化铌、碳酸镧为主要原料 ,通过液 -液反应和液 -固反应两种途径合成了正铌酸镧 (LaNbO4)无定形前驱体粉末 ,其中液 -液途径反应迅速完全 ;液 -固途径则能获得较均匀的粒度 .采用这两种途径均能获得d50 <1μm的粉末 .对有关机理进行的X射线衍射和扫描电镜 (SEM )分析表明 ,两种途径条件下合成的粉末经 10 0 0℃焙烧后均能获得LaNbO4晶体 ,而两种途径合成过程中的反应机理则完全不同
Abstract：Lanthanum orthoniobate (LaNbO 4) amorphous precursors were prepared by coprecipitation approach, using Nb 2O 5 and La 2(CO 3) 3 as the raw materials. Two methods have been developed. One is in a liquid_liquid system and the other one is in a liquid_solid system. The liquid_liquid method is easy to be realized and completed quickly, while the liquid_solid method has advantage of uniform particle size to be processed. Both the two processes can obtain LaNbO 4 with d 50 <1 μm. Powder characteristics before and after calcinations were studied by X _ray diffraction, and the morphology of the particles was studied by SEM micrograph. The result shows that while both methods can obtain LaNbO 4 crystalline after being calcined under 1 000 ℃, the reactions and mechanisms involved are quite different.
[1] TsunekawaS ,TakeiH .TwinningstructureofferroelasticLaNbO4andNdNbO4crystals[J].PhysStatSol(a),1978,50:695—699.
[2] TsunekawaS ,HaraK ,NishitaniR .ObservationofferroelasticdomainsinLaNbO4byatomicforcemicroscope[J].MaterTrans,1995,36(9):1188—1191.
[3] TsunekawaS ,KasuyaA ,NishinaY .Shapeandsizecontrolsofmicro_domainsinLaNbO4crystals[J].MaterSciEng,1996,A217/218:215—217.
[4] LiJian,WaymanCM .Monoclinic_to_tetragonalphasetransfor mationinaceramicrare_earthorthoniobatesLaNbO4[J].JAmCeramSoc,1997,80(3):803—806.
[5] LiJian,WaymanCM .Domainboundaryanddomainswitchinginaceramicrare_earthorthoniobatesLaNbO4[J].JAmCeramSoc,1996,79(6):1642—1648.
[6] MaschioS ,PezzottiG ,SbaizeroO .EffectofLaNbO4additiononthemechanicalpropertiesofceria-tetragonalzirconiapolycrystalmatrices[J].JEurCeramSoc,1998,18:1779—1785.
[7] MaschioS ,BachiorriniA ,DimonteR .Preparationandcharacter izationofLaNbO4fromamorphousprecursors[J].JMaterSci,1995,30:5433—5437.
[8] LiJian,WaymanCM .Compressivebehavioranddomain_relatedshapememoryeffectinLaNbO4ceramics[J].MaterLett,1996,26:1—7
基本信息:
中图分类号:TB44
引用信息:
[1]张志力,周浪,李永绣,黄惠珍.无定形正铌酸镧前驱体微粉的化学共沉淀法合成[J].硅酸盐学报,2001(05):484-487.
基金信息:
江西省自然科学基金项目 ( 995 0 0 30 ) ;; 清华大学新型陶瓷与精细工艺国家重点实验室开放课题 (KF0 0 0 1)
2001-10-26
2001-10-26