PL244549B1 - Substitutional confined solid solution in a binary transition metal oxide system containing vanadium, yttrium and oxygen and a method for its preparation - Google Patents

Abstract

The subject of the application is a substitutional, limited solid solution in a binary system of transition metal oxides, according to the invention, containing vanadium, yttrium and oxygen with the general formula Y_2-xV_xO<sub >3+x</sub>, where 0.00<x≤0.40, which means that it is formed in the concentration range of its components from 0.00% to 20.00% mol V<sub>2</sub >O₅. The application also includes a method for producing a substitutional, limited solid solution containing vanadium, yttrium and oxygen, according to the invention, consisting in mixing and grinding yttrium and vanadium oxides, which is characterized by mixing vanadium(V) oxide in an amount of not more than 20 00 mol% and yttrium(III) oxide in an amount of at least 80.00 mol%, the sum of the contents of V₂O₅ and Y<sub>2</sub >O₃ is always 100.00 mol%. Then, the mixture of oxides obtained in this way is ground in a high-energy planetary ball mill at a speed of 550 rpm in an air atmosphere with a ratio of the mass of grinding media (grinding material - zirconium(IV) oxide) to the mass of the sample oxide mixture (BPR) of 20: 1 preferably, in at least two stages of three hours each, and after each stage the samples are cooled to room temperature and triturated to obtain a product with the general formula Y_2-xV<sub>x</ sub>O_3+x, where 0.00<x≤0.40.

Description

Description of the invention

The subject of the invention is a substitutional, limited solid solution in a binary system of transition metal oxides containing yttrium, vanadium and oxygen, and a method for its production in the binary system of vanadium(V) oxide-yttrium(III) oxide. Compounds containing yttrium, vanadium and oxygen are used as inorganic phosphors in the production of plasma displays (LEDs), light-emitting diodes and fluorescent lamps.

Compounds containing yttrium, vanadium and oxygen are known from the literature and are formed as a result of the reaction between V2O5 and Y2O3 oxides. Such compounds include yttrium vanadates with the formulas: YVO4 (R.C. Ropp, Mat. Res. Bull. 10 (1975) 271-276), Y8V2Oi7 (E.M. Levin, J. Am. Ceram. Soc. 50 (1978) 381 -382) IYioV202o (O. Yamaguchi, J. Electrochem. Soc. 136 (2006) 1557-1560) and solid solutions whose matrices are the mentioned compounds (M. Piz, E. Filipek, Ceram. Int. 47 (2021) 12327 -12333). The compounds YVO4, Y8V2Oi7 and Y10V2O20 are mainly obtained by high-temperature reactions between vanadium(V) oxide and yttrium oxide in the temperature range from 600 to 1450°C. It is known from the literature M. Piz, P. Dulian, E. Filipek, K. Wieczorek-Ciurowa and P. Kochmański Journal of Materials Science 53 (2018) 13491-13500 a limited solid solution phase containing vanadium, ytterbium and oxygen with the general formula written as Yb2-5n2xV3xO3, where 0.00<x<0.1667 or Yb2-xVxO3+x, where 0.00<x<0.60. A method of preparing this phase is known from the literature provided. The phase is obtained by high-energy milling by homogenizing and then grinding a mixture of V2O5 and Yb2O3 oxides in a high-energy planetary ball mill for 6 hours at 550 rpm in an air atmosphere at the ratio of the mass of grinding media to the mass of the sample BPR (ball to powder ratio). ) of 20:1. The material of the grinding media was zirconium(IV) oxide.

The technical problem was related to the development of conditions and a synthesis method that would allow obtaining a previously unknown phase of the solid solution type, containing yttrium, vanadium and oxygen, with a Y2O3 structure, formed in the binary system of vanadium(V) oxide-yttrium oxide. Commonly used synthesis methods, such as: high-temperature heating of V2O5 and Y2O3 mixtures, co-precipitation from solutions containing NH4VO3 and Y(NO3)3 + 6H2O, or sol-gel, have always led to the preparation of known compounds, namely YVO4, Y8V2Oi7 or YioV202o . The solid solution phase with a Y2O3 structure and a designated range of homogeneity creates opportunities to design its physicochemical properties, which is important for finding areas of its applications.

The solid solution according to the invention has not been described in the literature so far.

A substitutional, confined solid solution in a binary system of transition metal oxides, according to the invention, containing vanadium, yttrium and oxygen with the general formula Y2-xVxO3+x, where 0.00<x<0.40, which means that it is formed in a range of concentrations its components from 0.00 to 20.00 mol% V2O5.

The method for producing a substitutional, limited solid solution containing vanadium, yttrium and oxygen, according to the invention, consisting in mixing and grinding yttrium and vanadium oxides, is characterized by mixing vanadium(V) oxide in an amount of not more than 20.00 mole% and yttrium(III) oxide in an amount of at least 80.00 mol%, with the sum of V2O5 and Y2O3 always being 100.00 mol%. The mixture of oxides thus obtained is then ground in a high-energy planetary ball mill at a speed of 550 rpm in an air atmosphere with a ratio of the mass of grinding media (grinding material - zirconium(IV) oxide) to the mass of the sample oxide mixture (BPR) of 20:1 , preferably, in at least two stages of three hours each, and after each stage the samples are cooled to room temperature and triturated to obtain a product with the general formula Y2-xVxO3+x, where 0.00<x<0.40.

A limited solid solution containing vanadium, yttrium and oxygen with the general formula Y2-xVxO3+x where x is in the range 0.00<x<0.40, is stable in a solid state in air in the temperature range from room temperature to ~800° C for x=0.40, then it decomposes, with the decomposition temperature Y2-xVxO3+x gradually increasing as the value of x decreases to x=0.00. The new solid solution has the Y2O3 structure, which means that it crystallizes in a cubic system. In a substitutional, confined solid solution, V ⁵⁺ ions are incorporated into the crystal lattice of the Y2O3 oxide constituting its matrix, in place of Y ³⁺ ions with a similar value of the ionic radius in the VI coordination.

The invention is described in more detail in the following embodiment. Powder diffractograms were recorded at room temperature using an Empyrean II diffractometer (PANalytical, the Netherlands) with a copper lamp (λCuKα = 1.5418A) and a graphite monochromator and with a goniometer travel step of 0.013° and a counting time of 70 s at the point. X-ray characteristics (in the range

PL 244549 Β1 angular 2Θ 10-60°) of the exemplary phase Y2-xVxO3+x for x = 0.10, which corresponds to the formula Yi,9oVo,io03,io, is shown in table 1, and for x =0.40 (Yi, eoVo,4o03,4o) in table 2.

Table 1

Lp- _dexp [nm] I/Io [%] 1 0.305 100 2 0.265 18.73 3 0.187 31.48 4 0.159 15.81

Table 2

^L P · _dexp [nm] I/Io [%] 1 0.307 100 2 0.266 22.62 3 0.188 25.56 4 0.160 14.30

wheredexp ^- interplanar distances, l/lo - relative intensities of the recorded diffraction lines

Example

Mixtures of V2Os and Y2O3 oxides, the exemplary compositions of which, in mol%, are given in Table 3, are homogenized by grinding. The obtained samples were ground in a high-energy planetary ball mill at a speed of 550 rpm in an air atmosphere with a ratio of grinding media mass (grinding material - zirconium(IV) oxide) to sample mass (BPR) of 20:1 in at least two stages of three stages. hours each. After each step, the samples are slowly cooled to room temperature and triturated.

A substitutional limited solid solution in a binary system of transition metal oxides containing vanadium, yttrium and oxygen with the general formula Y2-xV _x O3+x, where 0<x<0.4, is obtained according to the example from mixtures of transition metal oxides: V2Os and Y2O3 according to with the reaction equation:

0.5xV2Os(s) + (l-0.5 _X )Y ₂ O ₃₍ s) Y2-xV _x O ₃ +x(r _S .)

Table 3

No. Oxide mixtures % mol X The phase pattern is Y ₂ -xVxO ₃₊ x V ₂ O ₅ Y2O3 1 5.00 95.00 0.10 Yl,wVo,w03JO 2 10.00 90.00 0.20 Yl,8oVo,2o03,20 3 16.67 83.33 0.33 Yl.67Vo.33O3,33 4 20.00 80.00 0.40 Yl.60V0.40O3.40

Claims (2)

1. A substitutional confined solid solution in a binary system of transition metal oxides, containing vanadium, yttrium and oxygen with the general formula Y2-xVxO3+x, where 0.00<x<0.40. 2. A method for producing a substitutional limited solid solution containing vanadium, yttrium and oxygen, consisting in mixing and grinding yttrium and vanadium oxides, characterized by mixing vanadium(V) oxide in an amount of not more than 20.00 mole% and yttrium oxide (III) in an amount of at least 80.00 mol%, where the sum of the V2O5 and Y2O3 content is always 100.00 mol%, and then the oxide mixture obtained is ground in a high-energy planetary ball mill at a speed of 550 rpm, in air atmosphere with a ratio of the mass of the grinding media to the mass of the oxide mixture of 20:1, preferably in at least two stages of three hours each, and after each stage the samples are cooled to room temperature and triturated, obtaining a product with the general formula Y2-xVxO3+ x, where 0.00<x<0.40.