Инд. авторы: | Borzdov Y.M., Khokhryakov A.F., Kupriyanov I.N., Nechaev D.V., Palyanov Y.N. |
Заглавие: | Crystallization of Diamond from Melts of Europium Salts |
Библ. ссылка: | Borzdov Y.M., Khokhryakov A.F., Kupriyanov I.N., Nechaev D.V., Palyanov Y.N. Crystallization of Diamond from Melts of Europium Salts // CRYSTALS. - 2020. - Vol.10. - Iss. 5. - Art.376. - ISSN 2073-4352. |
Внешние системы: | DOI: 10.3390/cryst10050376; РИНЦ: 43291899; WoS: 000541423400048; |
Реферат: | eng: Diamond crystallization in melts of europium salts (Eu-2(C2O4)(3)center dot 10H(2)O, Eu-2(CO3)(3)center dot 3H(2)O, EuCl3, EuF3, EuF2) at 7.8 GPa and in a temperature range of 1800-2000 degrees C was studied for the first time. Diamond growth on seed crystals was realized at a temperature of 2000 degrees C. Spontaneous diamond nucleation at these parameters was observed only in an Eu oxalate melt. The maximum growth rate in the europium oxalate melt was 22.5 mu m/h on the {100} faces and 12.5 mu m/h on the {111} faces. The diamond formation intensity in the tested systems was found to decrease in the following sequence: Eu-2(C2O4)(3)center dot 10H(2)O > Eu-2(CO3)(3)center dot 3H(2)O > EuF3 > EuF2 = EuCl3. Diamond crystallization occurred in the region of stable octahedral growth in melts of Eu3+ salts and in the region of cubo-octahedral growth in an EuF2 melt. The microrelief of faces was characterized by specific features, depending on the system composition and diamond growth rate. In parallel with diamond growth, the formation of metastable graphite in the form of independent crystals and inclusions in diamond was observed. From the spectroscopic characterization, it was found that diamonds synthesized from Eu oxalate contain relatively high concentrations of nitrogen (about 1000-1200 ppm) and show weak PL features due to inclusions of Eu-containing species.
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Ключевые слова: | CENTERS; FLUID; MANTLE; HIGH-PRESSURE; characterization; defects; rare-earth ions; crystal morphology; crystallization; high temperature; high-pressure; diamond; CARBON; |
Издано: | 2020 |
Физ. характеристика: | 376 |