Ferroelectric Behavior of Pb(Mg1/3Nb2/3)O3 (PMN) Obtained by the Sol-Gel Method

详细信息    查看全文

• 作者：Purificaci&oacute ; n Escribano ; Hé ; ctor Beltrá ; n ; Eloisa Cordoncillo ; Germ&agrave ; Garcí ; a-Belmonte ; Luisa Ruiz ; José ; M Gonzá ; lez-Calbet ; and Anthony R. West
• 刊名：Chemistry of Materials
• 出版年：2001
• 出版时间：February 2001
• 年：2001
• 卷：13
• 期：2
• 页码：415 - 419
• 全文大小：176K
• 年卷期：v.13,no.2(February 2001)
• ISSN：1520-5002

文摘

The ferroelectric behavior of lead magnesium niobate perovskite, obtained by sol-gelmethods, has been investigated in three samples with compositions based on Pb(Mg_1/3Nb_2/3)O₃(PMN) to which an excess of PbO and MgO has been added. Electron probe microanalysis (EPMA) showed a single phase of stoichiometry PbMg_0.33Nb_0.68O_3.02 in sample 2,PbMg_0.36Nb_0.69O_3.09 in sample 3, and PbMg_0.32Nb_0.67O₃ together with PbO in sample 4.Permittivity measurements reach values higher than 22 000 for sample 2 and 11 000 forsamples 3 and 4. A microstructural characterization of the first two samples, by means ofhigh-resolution electron microscopy, shows the presence of small domains of double periodicityinserted in a matrix with a single cubic perovskite structure. The concentration of doubledomains is higher in the first sample. The third sample shows a mixture phase due to thepresence of PbO. The relationship between microstructure and electrical behavior showsthat the permittivity values are related not only to the existence of a single PMN phase butalso to Pb:(Mg + Nb) ratios close to 1 and Mg:Nb ratios close to 0.5.