GOST 23862.14-79
GOST 23862.14−79 Lanthanum, gadolinium, yttrium and their oxides. Method of determination of impurities of oxides of neodymium, samarium, europium and erbium (with Amendments No. 1, 2)
GOST 23862.14−79
Group B59
INTERSTATE STANDARD
LANTHANUM, GADOLINIUM, YTTRIUM AND THEIR OXIDES
Method of determination of impurities of oxides of neodymium, samarium, europium and erbium
Lanthanum, gadolinium, yttrium and their oxides. Method of determination of impurities as oxides of neodymium, samarium, europium and erbium
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 neodymium, samarium, europium and erbium in the lanthanum, gadolinium, yttria and their oxides.
The method is based on excitation of a mercury or xenon lamp in the luminescence spectra of rare earth elements — impurities in the crystal of the analyzed materials and the registration of the received radiation. Impurities find a method of additives.
Intervals determined by a mass fraction of impurities of oxides:
| in the lanthanum and its oxides: | |
| neodymium | from 5·10 |
| erbium | from 5·10 |
| in yttria and its oxide: | |
| neodymium | from 1·10 |
| in gadolinium and its oxide: | |
| Samaria | from 5·10 |
| europium | from 1·10 |
(Changed edition, Rev. N 1, 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 23862.0−79.
2. APPARATUS, MATERIALS AND REAGENTS
The fluorescence spectrophotometer of the type М850 or similar.
Set for detection of luminescence spectra (figure).
1 illuminator OSL-1 with a mercury lamp DRSH-250; 2 — filter UFS-6; 3 — initiation; 4 — cuvette with crystallophosphorus; 5 — condenser; 6 — spectrograph ISP-51; 7 — a regulator of speed of rotation of the prism; 8 — high voltage regulated power supply VSV-2; 9 — attachment of photovoltaic solar cells-1 with photomultiplier FEU-22; 10 — recording potentiometer EPP-17M-2
A muffle furnace with a thermostat that provides temperature to 1200 °C.
Tile electric.
Muffle furnace with thermostatic control, providing the temperature to 120 °C.
Mortars and pestles, agate or from glass.
Crucibles porcelain N 3.
The quartz Cup with a capacity of 30−50 cm.
Nitric acid of high purity according to GOST 11125−84 diluted 1:1.
Ammonium undeviatingly according to GOST 9336−75, H. h
Sodium nitrate according to GOST 4168−79, a solution with a concentration of 50 g/DM.
Hydrochloric acid of high purity according to GOST 14261−77 diluted 1:1.
Sodium chloride according to GOST 4233−77, H. h, solution with concentration 10 g/DM.
Deionized water (twice).
The technical rectified ethyl alcohol GOST 18300−87.
Neodymium oxide brand BUT-SS.
Erbium oxide brand of Ero-1.
Samarium oxide brand Smo-1.
Europium oxide brand Evo-1.
Solutions I spare neodymium, samarium, europium and erbium containing 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 cm
of 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.
I working solutions containing 1 µg/cmREE (calculated as oxide), is prepared by dilution of the replacement solutions I water 1000 times.
Solution II spare neodymium containing 1 mg/cmneodymium (calculated as oxide): 100 mg of neodymium oxide were placed in a glass with a capacity of 50 cm
, moistened with water, poured 0,5−1 cm
of nitric 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.
II working solution containing 1 µg/cmneodymium (calculated as oxide), is prepared by dilution of the reserve water solution II to 1,000 times.
Sec. 2. (Changed edition, Rev. N 1, 2).
3. ANALYSIS
3.1. Preparation of crystal
3.1.1. A crystal of lanthanum prepared as follows. Four quartz Cup was placed in 300 mg of the sample of an oxide of lanthanum (or the corresponding amount of metal), pour in 2 cmof sodium chloride solution and 0.5 cm
of hydrochloric acid. In two cups of injected working solutions I of neodymium and erbium (1 µg/cm
) so that the content of these REE were larger than the expected content of the sample is 1.5−3 times. Then all four cups are placed on the electric stove, heat until dissolved, evaporated to dryness, calcined in a muffle furnace at 700−750 °C for 20−25 min and cooled to room temperature.
3.1.2. A crystal of yttrium in a porcelain crucible placed in 300 mg of the sample of an oxide of yttrium (or the corresponding amount of metal), pour in 2 cmof nitric acid. Two of the crucible enter the working solution II neodymium (1 µg/cm
) so that the content of neodymium was larger than the expected concentration in the sample is 1.5−3 times. All four of the crucible is placed on the electric stove, heat until dissolved, evaporated to dryness, calcined in a muffle furnace at 950−1000 °C for 3−5 min and cooled to room temperature.
In each Cup add 165 mg vadeevaloo ammonium was mixed thoroughly with a glass rod, add 1.5 cmof sodium nitrate solution, stirred, dried in an oven at 100−110 °C, calcined in a muffle furnace at 1000−1100 °C for 1 h and cooled to room temperature.
3.1.1,
3.1.3. The crystal of gadolinium in quartz Cup is placed 500 mg of the sample of an oxide of gadolinium. In two cups of injected working solutions I, samarium, europium, so that the value of the mass fraction of the designated impurities exceed their estimated value in the sample is 1.5−3 times (weight of the sample should be completely covered with solution). In the other two cups poured by 0,5−1 cmof water. The contents of each Cup gently stirred PTFE stick, gently, to avoid ejection of the sample is evaporated on a hot plate to dryness, transferred to a mortar, add 275 mg vadeevaloo ammonium triturated for 10−15 minutes, adding the alcohol to maintain the mixture in the wet state, transferred again in a quartz Cup, gently dried on a hot plate, and calcined in a muffle furnace at 1000−1100 °C for 1 h and cooled to room temperature (no presence of bright yellow and brown spots).
(Added, Rev. N 2).
3.2. Excitation and registration of luminescence spectra
Every crystalliser ground in a mortar and placed in a cuvette with a quartz window. In the analysis of each sample excite and record the luminescence spectra of crystal phosphors four consecutively, starting with great supplements.
(Changed edition, Rev. N 2).
3.2.1. In the analysis of lanthanum, yttrium and their oxides crystallophosphorus a cuvette is placed in the chamber (see drawing). The spectrum of luminescence excited by radiation of a mercury lamp DRSH-250, passed through a color filter UFS-6, in the range 365−440 nm. The input and output slit of a spectrograph ISP-51 open as possible. The voltage on the photomultiplier PMT-22 1000−1100 V.
3.2.2. In the analysis of gadolinium and its oxide crystallophosphorus a cuvette placed in the sample compartment of a fluorescence spectrophotometer М850. The spectrum of luminescence excited by radiation of a xenon lamp using a wavelength of 330 nm.
The slit width of the monochromator emission — 0.5 nm.
The slit width of the monochromator excitation and 20 nm.
3.2.1,
4. PROCESSING OF THE RESULTS
4.1. In each registrarme measure the height () of the peak of the analytical lines of impurity element (see table.1).
Table 1
| Item |
The recorded portion of the spectrum, nm |
Wavelength of analytical lines, nm |
Basis |
| Neodymium |
885−900 |
893 |
In Lantana |
| 880−910 |
893 |
In ittrii | |
| Erbium |
540−560 |
549 |
In Lantana |
| Samarium |
630−660 |
649 |
In gadolinium |
| Europium |
610−630 |
619 |
In gadolinium |
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 determined by the oxide additive, %;
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 3.1, 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.
Discrepancies in the results of two parallel determinations or the results of the two analyses (the ratio of largest to smallest) should not exceed values of allowable differences specified in table.2.
Table 2
| Basis |
Determined by the impurity |
The permissible divergence |
| Lanthanum and oxide |
The oxide of neodymium |
2,0 |
| The oxide of erbium |
2,5 | |
| Yttrium and its oxide |
The oxide of neodymium |
3,0 |
| Gadolinium and its oxide |
The oxide of samarium |
2,0 |
| Oxide europium |
1,8 |
4.1, 4.2. (Changed edition, Rev. N 2).
