ИСТИНА

Установить особенности локальной и протяженной структуры серии поликристаллических образцов на основе LLZ (Li7La3Zr2O12) частично замещенного ниобием (20, 25 и 40%), алюминием и танталом

Будут установлены особенности локальной и протяженной структуры серии поликристаллических образцов замещенных Li7La3Zr2O12 со структурой граната

Compounds of the substituted Li7La3Zr2O12 family with a garnet structure are of interest as ionic conductors and electrode materials, including for Li-ion power sources. Li7La3Zr2O12 is known to have cubic and tetragonal crystalline modifications, which differ in the distribution of lithium atoms, which affects the ionic conductivity of the material. Heterovalent doping of Li7La3Zr2O12 with Nb4+/Nb5+, Ta4+/Ta5+, Al3+ ions can lead to distortion of the local structure and an increase in ionic conductivity. However, the closeness of the scattering power (number of electrons) of Nb and Zr ions does not allow reliable localization of Nb atom positions in the structure using X-ray diffraction methods. Studying the local structure using the pair distribution function PDF analysis has an advantage, since the ionic radii of Zr4+ and Nb4+/Nb5+ differ, which will be reflected in the interatomic distances in the structure. The aim of the work is to establish the features of the local and extended structure of a series of polycrystalline samples based on LLZ (Li7La3Zr2O12) partially substituted with niobium (20, 25 and 40%), aluminum and tantalum. As part of the work on studying the structure using the PDF method for a series of samples substituted with Li7La3Zr2O12, the total X-ray scattering was measured in the range of Q = 0.3 – 7.7 Å–1. Based on the obtained data, PDF functions were constructed in the range of r = 0 – 60Å. The experimental PDF data were described by the Li7La3Zr2O12 structure model, and conclusions were made about the substitution of La and Zr positions when doped with Nb and Ta atoms.

В рамках работы по исследованию структуры методом PDF для серии образцов замещенных Li7La3Zr2O12 измерено полное рентгеновское рассеяние в диапазоне Q = 0.3 – 7.7 Å–1. На основании полученных данных построены PDF-функции в диапазоне r = 0 – 60Å. Проведено описание экспериментальных PDF-данных моделью структуры Li7La3Zr2O12, сделаны выводы о замещении позиций La и Zr при легировании атомами Nb и Ta.