PIMNT单晶生长用多晶料的固相合成

Solid-state Synthesis of Polycrystalline Material for PIMNT Single Crystal Growth

以In2O3、Nb2O5、4MgCO3.Mg(OH)2.4H2O、TiO2、PbO为初始试剂,先合成出前体化合物MgNb2O6和InNbO4;按照0.25Pb(In1/2Nb1/2)O3-0.44Pb(Mg1/2Nb2/3)O3-0.31PbTiO3的组分比例,添加1.5 mol%过量PbO,通过高温固相反应合成出PIMNT多晶料。X射线粉末衍射、差热/热重分析表明,PIMNT多晶系钙钛矿结构的固溶体化合物。采用本实验合成PIMNT多晶料锭,通过坩埚下降法成功生长出25 mm直径的PIMNT单晶,证实采用预先合成多晶料有助于钙钛矿相PIMNT单晶的稳定生长。

Using In2O3, Nb2O5, 4MgCO3·Mg（OH）2·4H2O,TiO2 and PbO as starting reagents, the precursors of MgNb2O6 and InNbO4 were synthesized by solid-state reaction. According to the molar ratio of 0.25Pb （ In1/2 Nb1/2 ）O3-0. 44Pb （ Mg1/2 Nb2/3 ）O3-0.31PbTiO3 with 1.5mol% excess PbO, PIMNT polycrystalline material were prepared by solid-state synthesis at elavated temperature. PIMNT polycrystalline material together with the precursor compounds were characterizied by XRD and differtialthermal analysis. The polycrystalline material was verified to be PIMNT solid-solution with perovskite structure. Using the synthesized polycrystalline material as the feed material, PIMNT single crystal with 25 mm in diameter was grown successfully by vertical Bridgman method. The results indicate that the presynthesized polycrystalline material is helpful to the steady growth of PIMNT single crystal with perovskite phase.