METHOD FOR DETERMINING THE DEGREE OF BORON CRYSTALLINITY Russian patent published in 2023 - IPC G01N23/2055 C01B35/02 

FIELD: material structure.

SUBSTANCE: determining the parameters of the crystal structure of materials. First, samples of powdered boron of heterogeneous composition are prepared by drying and sieving to equalize the dispersion composition, which is characterized by the presence of amorphous and crystalline components. Then the sample is placed in bulk in a glass cuvette with a central cavity diameter of 20-25 mm and a depth of 1-2 mm, and the cuvette is placed horizontally in the measuring cell of the X-ray diffractometer. After that, a triple shooting is carried out in an X-ray diffractometer with a vertical angle gauge complete with a graphite monochromator in the shooting mode in the range of scattering angles 2θ =(7-80)° , pitch 0.02° , with speed 1°/min, at a shutter speed of 1.2 s. In a boron sample, the degree of crystallinity (DC) is determined by selecting the area of scattering angles in which the maxima corresponding to the scattering of the amorphous component and reflection from crystalline planes are completely recorded. Then, using the software with which the X-ray diffractometer is equipped and the algorithm of which provides graphical processing of the recorded signals, the graphical separation of the profiles of the crystalline and amorphous components and the automatic calculation of their integral intensities are performed. SC is determined by the Ruland-Wonk method in the selected range of scattering angles according to the formula:

where I_a, I_cr are integral intensities of the amorphous and crystalline parts of the diffraction spectrum, pulse/s⋅°. The obtained SC values are averaged according to the number of samples. A correction is made to the calculated average value, taking into account the error determined on the basis of measurements obtained after irradiation in an X-ray diffractometer of control samples from a set of at least 10 reference mixtures with a boron content with a given mass content of the crystalline phase from 0 to 100% with a step of 10% according to the formula

where SC_c is a corrected value; SC_av is an average value in accordance with the number of samples.

EFFECT: possibility to overcome the difficulties caused by the heterogeneity of the phase composition of the analyzed boron samples and the difficulty of isolating individual phases, and the possibility of quantitative determination of the degree of boron SC, increasing information content, reliability and reproducibility.

1 cl, 2 dwg, 3 tbl, 1 ex