Abstract

The (CsCl–NaCl–KCl)_eut–IrCl₃ melt is promising for the production of iridium coatings and composites. The liquid temperature and the electrical conductivity are determined for several compositions of the melt by thermal analysis and impedance spectroscopy. The temperature ranges of liquidus (753–983) ± 5 K and solidus (751–755) ± 4 K are established and the corresponding parts of the phase diagram for the quasi-binary system (CsCl–NaCl–KCl)_eut–(0–2.12 mol %) IrCl₃ is plotted. The lowest liquidus temperature is shown to be observed for the melt containing 1.4 mol % IrCl₃. The increase in the liquidus temperature in the molten mixtures with more than 1.5 mol % IrCl₃ is explained by the formation of the Cs₃IrCl₆ compound, which was detected by XRD analysis. The electrical conductivity of the melts (in the homogeneity region) is found to linearly decrease as the temperature decreases or the IrCl₃ concentration increases. The coefficients that describe the temperature dependences of the electrical conductivity of the (CsCl–NaCl–KCl)_eut–(0–2.12 mol %) IrCl₃ melts are determined. For all the studied iridium-containing compositions, the average temperature coefficient is (2.35 ± 0.02) × 10^–3 Ω^–1 cm^–1 K^–1. The addition of 1 mol % IrCl₃ leads to a decrease in the electric conductivity by about 7%. It is found that the operating temperature can be decreased to ~800 K in the melt with iridium trichloride concentrations of 1.4–1.5 mol %; the process temperature can be varied from 850 K to 1030 K at lower and higher IrCl₃ contents depending on the electrodeposition conditions.

中文翻译：

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含IrCl 3的熔融CsCl–NaCl–KCl共晶的液相线温度和电导率

摘要

（CsCl–NaCl–KCl）_eut – IrCl ₃熔体有望用于生产铱涂层和复合材料。通过热分析和阻抗谱法确定几种熔体成分的液体温度和电导率。建立了液相线（753–983）±5 K和固相线（751–755）±4 K的温度范围，并且准二元系统（CsCl–NaCl–KCl）的相图的相应部分_eut –（0绘制了–2.12 mol％）IrCl ₃的图。对于包含1.4 mol％IrCl ₃的熔体，观察到最低液相线温度。含1.5mol％以上的IrCl ₃的熔融混合物的液相线温度升高通过XRD分析检测到的Cs ₃ IrCl ₆化合物的形成来解释这一点。发现熔体的电导率（在均匀性区域）随着温度降低或IrCl ₃浓度增加而线性降低。确定了描述（CsCl–NaCl–KCl）_析出物–（0–2.12 mol％）IrCl ₃熔体的电导率的温度依赖性的系数。对于所有研究的含铱的组合物中，平均温度系数为（2.35±0.02）×10 ^-3 Ω ^-1厘米^-1 ķ ^-1。添加1 mol％IrCl ₃导致电导率降低约7％。研究发现，在三氯化铱浓度为1.4–1.5 mol％的情况下，熔体中的工作温度可以降低至〜800K。取决于电沉积条件，在较低和较高IrCl ₃含量的情况下，工艺温度可以在850 K至1030 K之间变化。