GOST 23862.15-79

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  ГОСТ 23862.15-79

GOST 23862.15−79 Yttrium and its oxide. Method of determination of impurities of oxides of praseodymium, neodymium, samarium, europium, terbium, dysprosium, holmium, erbium, thulium and ytterbium (with Amendments No. 1, 2)

GOST 23862.15−79

Group B59

INTERSTATE STANDARD

YTTRIUM AND ITS OXIDE

Method of determination of impurities of oxides of praseodymium, neodymium, samarium, europium, terbium, dysprosium, holmium, erbium, thulium and ytterbium

Yttrium and its oxide. Method of determination of such impurities as oxides of praseodymium, neodymium, samarium, europium, terbium, disprosium, helmium, erbium, tulium and ytterbium

ISS 77.120.99
AXTU 1709

Date of introduction 1981−01−01

The decision of the State Committee USSR on standards on October 19, 1979 N 3988 date of introduction is established 01.01.81

Limitation of actions taken by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (ICS 11−95)

EDITION with Amendments No. 1, 2 approved in April 1985, may 1990 (IUS 7−85, 8−90).


This standard establishes a fluorescent method for the determination of oxides of rare earth elements in yttria and its oxide.

The method is based on excitation of a mercury lamp spectrum of luminescence of rare-earth elements in the crystal of the analyzed materials and the registration of the received radiation. Mass fraction of impurities find by the method of additions.

Intervals determined by a mass fraction of impurities of oxides:

(Changed edition, Rev. N 1).

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis according to GOST 23862.0−79.

2. APPARATUS, MATERIALS AND REAGENTS

The fluorescent spectrophotometer MPF-4 of Hitachi, or similar device.

Set for detection of luminescence spectra on the basis of a MDR-3 grating with 600 lines/mm (see drawing 1).

1 illuminator OTS-18 with a mercury lamp DRSH-250; 2 — filter UFS-2; 3 — initiation; 4 — cuvette with crystallophosphorus; 5 — condenser; 6 — monochromator MDR-3; 7 — photomultiplier FEU-62; 8 — amplifier U5−6; 9 — recorder KSP-4; 10 — high voltage rectifier, VS-22

Damn.1

The photomultiplier FEU-62.

Muffle furnace with thermostatic control, providing heating to 1200 °C.

Tile electric.

Libra torsion type VT-500 or similar.

Crucibles porcelain No. 1 or No. 2.

Ammonium undeviatingly meta GOST 9336−75, H. h

Sodium nitrate according to GOST 4168−79, H. h, solution with a concentration of 50 g/DM.

Hydrochloric acid of high purity according to GOST 14261−77 diluted 1:1.

Ammonium fluoride according to GOST 4518−75, H. h

Potassium fluoride according to GOST 20848−75, H. h, solution with a concentration of 50 g/DM.

Sodium sulfate according to GOST 6053−77, H. h, solution with a concentration of 50 g/DM.

Sulfuric acid GOST 4204−77, H. h., diluted 1:2.

Oxides of praseodymium, neodymium, samarium, europium, terbium, dysprosium, holmium, erbium, thulium, ytterbium with a purity not less than 99%.

Replacement solutions containing each 1 mg/cmof one of REE (calculated as oxide): 100 mg of the REE oxides were placed in a glass with a capacity of 50 cm, moistened with water, poured 0,5−1 cmof hydrochloric acid, heated on a hot plate until dissolved, cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

Solutions working I containing 1 ug/cmof one of REE (calculated as oxide), is prepared by dilution replacement solution with water to 1000 times.

The working solution II, containing 1 µg/cmneodymium, samarium, europium, dysprosium, holmium, erbium, thulium, ytterbium (based on oxide): in a volumetric flask with a capacity of 1000 cmmake 1 cmof spare solutions listed REE, adjusted to the mark with water and mix.

3. ANALYSIS

3.1. Conversion of metal yttrium to the oxide — GOST 23862.0−79.

3.2. Preparation of crystal

3.2.1. The crystal for the separate determination of each impurity in the porcelain crucible is placed on 150 mg of the sample. One enter the crucible working solution I is determined by the impurities so that the additive content was approximately equal to the estimated impurity content in the sample. In the second crucible Supplement must exceed the expected content of this impurity in the sample twice.

In the remaining two crucibles, samples moistened with 1−2 drops of water.

3.2.2. In the determination of terbium in each crucible add 0.1 cmof a solution of sulphate of sodium, 0.3 cmof sulfuric acid.

The crucibles were placed in electric cooker, evaporated to dryness, calcined in a muffle furnace at 1100 °C for 1 h and cooled to room temperature.

3.2.3. In determining each of the other four impurities of the crucible is placed on the electric stove, evaporated to dryness and cooled to room temperature.

3.2.3.1. In the determination of praseodymium in each crucible add 60 mg of ammonium fluoride and 0.15 cmof a solution of potassium fluoride, dried on the hotplate, and calcined in a muffle furnace at 830 °C for 45 min and cooled to room temperature.

3.2.3.2. In the determination of each of the impurities — neodymium, samarium, europium, dysprosium, holmium, erbium, thulium, ytterbium, in each crucible, add 100 mg vadeevaloo ammonium was mixed thoroughly with a glass rod, add 0.25 cmof sodium nitrate solution, stirred, dried to dryness on the hotplate, and calcined in a muffle furnace at 900 °C for 1 h and cooled to room temperature.

3.2.3.3. If the mass fraction of each of the listed in paragraph 3.2.3.2. impurities does not exceed 5·10% supplementation producing according to claim 3.2 using a working solution II. The result is a crystal with additions of all of these impurities.

3.3. Excitation and registration of luminescence spectra

The crystal is placed in a cuvette with a quartz window.

When using a ditch, without a quartz window (Fig.2) use the following method: the cell (4) is placed on the polished surface of the substrate (5) side and attach a magnet (1). In a cuvette, the sample is poured from top (2) and pressed by the punch (3) with a force of 10 kg.

1 — magnet; 2 — sample; 3 — punch; 4 — cuvette; 5 — substrate

Damn.2

In the determination of each impurity excite and record the luminescence spectra of crystal phosphors four sequentially starting with most supplements.

(Changed edition, Rev. N 2).

3.3.1. Determination of praseodymium, samarium, europium, terbium, dysprosium, holmium, erbium, thulium spend on a fluorescent spectrophotometer MPF-4. The spectrum of luminescence excited by radiation of a xenon lamp at a wavelength of 320 nm for all impurities, except praseodymium, for which the excitation wave length of 250 nm. The voltage on the photomultiplier — 800, the entrance slit fully open, inlet filter — black filter on the output — UV-43 for all impurities, except for thulium, for which the filter output — R-62. The wavelengths of emission lines are given in table.1.

Table 1

3.3.2. Determination of the mass fraction of neodymium and ytterbium performed on the system based on the MDR-3 (figure 1) with a grating 600 gr/mm.

The spectrum of luminescence excited by radiation of a mercury lamp.

Inlet filter — a UFS-2 filter at the output of the COP. Other conditions of registration are given in table.2.

Table 2

4. PROCESSING OF THE RESULTS

4.1. In each registrarme measure the height () of the peak of the analytical lines of impurity element.

Two parallel values of and obtained with two registrovanym for crystal phosphors prepared with the samples without additives, find arithmetic mean value .

Mass fraction of each of the designated oxides () in percent is calculated by the formula

,

where  — mass fraction of additives determined by the impurity, %;

the peak height of the analytical lines in registrarme obtained for crystallophosphorus prepared from the samples with additive.

If the value of supplements do not meet the requirements laid down in paragraph 3.2, the analysis is repeated with the introduction of new additives.

4.2. Under the control of reproducibility of results of parallel measurements on two parallel values and calculated values and the results of parallel measurements.

The differences between them and the results of the two analyses (the ratio of largest to smallest) should not exceed the value of permissible differences, is equal to 2.5.