The method of obtaining powder of oxide composition is pb(mg1/3nb2/3o3)
The invention relates to the field of production of materials for electronic engineering, in particular to obtain powder of the oxide of the composition Pb(Mg1/3Nb2/3O3). The result is a decrease in the temperature of heat treatment of the product, increasing product yield and increase its purity. Mix the niobium hydroxide with aqueous solutions of acetates of lead and magnesium. The concentration of lead in solution 0,110-0,120 mol/l and magnesium - 0,580-0,590 mol/l, the Deposition is carried out at a pH of 5-6. The obtained precipitate was separated from the mother liquor. Carry out the heat treatment of the product at 800-850oC. 1 table. The invention relates to the field of obtaining oxide powder of composition Pb(Mg1/3Nb2/3O3) and can be used for the manufacture of electronic materials technology.A method of obtaining magnanimity lead (PMN) by mixing in stoichiometric proportion of the oxide of niobium, magnesium and lead, and carrying out annealing the mixture at 900-1000o(S. L. Swarts, Shrout, T. R. Fabrication of Perovskite Lead Magnesium Niobate // Mater. Res. Bull. 1982. Vol.17. P. 1245-50).The disadvantage of this method is the high temperature synthesis and heterogeneity of the product (in addition to the required phase with perovskite structure, nd the essence and the achieved result is a method of obtaining magnanimity lead with perovskite structure by mixing a suspension of niobium pentoxide in a solution of carbonate and ammonium hydroxide with aqueous solutions of nitrate salts of lead and magnesium, solids separation. The target product is obtained by heat-treating the dried precipitate at 1250o(A. C. the USSR 632654, MKI 01 G 33/00, 35/00; B. I. 42. 1978).The disadvantage of this method is the high temperature heat treatment of the final product and the target product in excess of 5% of phase with the pyrochlore structure, the presence of which reduces the operating characteristics magnanimity lead.The technical result of the invention is to reduce the temperature of the heat treatment of the final product, increasing the yield of the target product and increase its purity.The invention consists in obtaining a powder of the oxide of the composition Pb(Mg1/2Nb2/3O3), which is achieved by mixing the niobium hydroxide with sodium acetate aqueous solution of magnesium and lead concentrations of metals in solution: lead 0,110-0,120 mol/l and magnesium 0,580-0,590 mol/l at pH 5-6, solids separation, and conducting heat treatment at 800-850oC.Example 1. For experience use powdered niobium hydroxide containing niobium pentoxide, niobium 74%, acetate salt solution of magnesium and lead concentrations of magnesium 0,580 mol/l, and lead 0,110 mol/L. the Mixture and shake dry hydroxide niobium in an amount of 8.0 góra. After settling suspension of solid phase is separated from the mother liquor. Heat treatment of the selected product is carried out at 800oC. According to x-ray phase analysis (XRD) of the obtained powder is a cubic phase magnanimity lead PbMg1/3Nb2/3O3.Examples 2-12 carried out analogously to example 1, and the modes shown in the table.Thus, our proposed method, unlike described in the prototype, allows the synthesis of oxide powder of composition Pb(Mg1/3Nb2/3O3) at a lower temperature, to increase the yield of the target product and to increase its purity (presence of side pyrochlore phase is not observed).
ClaimsThe method of obtaining powder of the oxide of the composition Pb(SB1/3Nb2/3About3) (PMN) comprising a mixture of compounds of niobium with an aqueous solution of salts of lead and magnesium, separating the resulting precipitate from the mother liquor and heat treatment, characterized in that compounds of niobium using the niobium hydroxide, and a solution of salts of lead and magnesium solutions of acetates of lead and magnesium concentrations of lead - 0,110-0,120 mol/l and magnesium - 0,580-0,590 mol/l, the method is carried out is
FIELD: production of ABO3-type methametallate (V) for laser, electrooptical, ferroelectric materials and special ceramics.
SUBSTANCE: fresh deposited metal (V) hydroxide (e.g. niobium, tantalum or mixture thereof) is brought into reaction with lithium or sodium hydroxide or mixture thereof at stoichiometric ratio in hydrogen peroxide with reagent agitation. Used hydrogen peroxide has concentration not less than 35 mass % and is cooled up to 00C to provide total component dissolution. Lithium hydroxide is used in solid form and has formula LiOHˇH2O. Sodium hydroxide is used in form of aqueous solution with concentration of 15.5-19.0 M. Precipitate is isolated by evaporation of obtained peroxide solution and baked at <7300C.
EFFECT: absence of side products, finished products with increased assortment.
7 cl, 8 ex