Low‐Temperature Route to Lead Magnesium Niobate

Abstract

Lead magnesium niobate, Pb(Mg,,3Nb213)03 (PMN), was pre-11. Experimental Procedure pared by a sol-gel technique using alkoxide precursors. The hydrolysis-condensation mechanism leads to a translucent gel which is dried under hypercritical conditions to avoid collapse of the porous texture. After drying, the aerogel exhibits a B-deficient pyrochlore structure which progressively inserts magnesium oxide when the temperature increases. Near PMN-perovskite phase. Above 1000°C, the loss of lead oxide mation of an A-deficient pyrochlore phase. [

Effect of sintering conditions on the pyrochlore phase content in PMN–PFN ceramics prepared by sol–gel process

“…Chaput et al 9 prepared PMN phase by a sol-gel method using alkoxide precursors. The pyrochlore phase was completely transformed into PMN pv phase around 700 • C. A colloidal sol-gel route represents the preparation of PMN and PMN-PFN systems from metal chlorides and nitrates.…”

“…Ananta and Thomas 11 developed two-stage mixed oxide synthetic routes for the preparation of single phases of lead-based complex perovskite PMN and PFN and two complex perovskite compounds at selected compositions in the PMN-PFN pseudo-binary system were prepared and characterized 12 . PMN is also synthetized by various wet chemical processing routes such as sol-gel, 9,[13][14][15][16] combustion synthesis, 17,18 coprecipitation, 19 molten salt synthesis, 20 citrate gel, 21,22 partial oxalate, 23,24 polymerized complex, 24,25 citrate complex 26 and a niobium tartarate complex 27 methods. The combination of the partial oxalate method with the columbite route and the Pechini method was used to obtain PMN powder at low temperature.…”

“…wolframite 8 ), wet chemical route, 9 and salt-based method. 10 In the conventional method (solid state reaction) the oxides (PbO, MgO and Nb 2 O 5 ) are weighted and mixed under dry or wet conditions.…”

Pb((Mg0.7Zn0.3)1/3Nb2/3)O3 Relaxor Ferroelectric Ceramics by a Reaction-Sintering Process

“…Lead based relaxor ferroelectric ceramics have been widely investigated for capacitor application [1][2][3][4]. Both Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) and Pb(Zn 1/3 Nb 2/3 )O 3 (PZN) have high dielectric constant (∼20,000 for PMN and ∼30,000 for PZN single crystals) [5].…”

Chemically Prepared Lead Magnesium Niobate Dielectrics

“…Two different methodologies will be discussed. Chaput and coworkers [4] have fabricated fine powders from translucent gels of PMN using alkoxide precursors and hypercritical drying (250°C and 6.3 MPa). A B-site deficient pyrochlore phase was formed for temperatures below 700"C, with a major percentage of perovskite phase being obtained by a 700°C thermal treatment.…”