Diamond crystallization in melts of europium salts (Eu₂(C₂O₄)₃·10H₂O, Eu₂(CO₃)₃·3H₂O, EuCl₃, EuF₃, EuF₂) at 7.8 GPa and in a temperature range of 1800–2000 °C was studied for the first time. Diamond growth on seed crystals was realized at a temperature of 2000 °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 μm/h on the {100} faces and 12.5 μm/h on the {111} faces. The diamond formation intensity in the tested systems was found to decrease in the following sequence: Eu₂(C₂O₄)₃·10H₂O > Eu₂(CO₃)₃·3H₂O > 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.

中文翻译：

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从Euro盐熔体中结晶出钻石

of盐（Eu ₂（C ₂ O ₄）₃ ·10H ₂ O，Eu ₂（CO ₃）₃ ·3H ₂ O，EuCl ₃，EuF ₃，EuF _2的熔体中的金刚石结晶）在7.8 GPa和1800–2000°C的温度范围内进行了首次研究。晶种上的金刚石生长是在2000°C的温度下实现的。仅在parameters草酸melt熔体中观察到这些参数下的自发金刚石成核。草酸euro熔体的最大生长速率在{100}面上为22.5μm/ h，在{111}面上为12.5μm/ h。发现测试系统中的金刚石形成强度按以下顺序降低：Eu ₂（C ₂ O ₄）₃ ·10H ₂ O> Eu ₂（CO ₃）₃ ·3H ₂ O> EuF ₃ > EuF ₂ = EuCl ₃。金刚石结晶发生在Eu ³⁺盐熔体中稳定的八面体生长区域和EuF ₂熔体中的立方八面体生长区域。面部的微浮雕具有特定特征，具体取决于系统组成和钻石生长速率。在金刚石生长的同时，观察到以独立晶体和夹杂物的形式形成亚稳石墨。通过光谱表征，发现用草酸Eu合成的钻石含有较高浓度的氮（约1000-1200 ppm），并且由于包含了含Eu物质而显示出较弱的PL特性。