The density as a function of temperature was determined for liquid iridium (Ir) and rhenium (Re) by means of shadow imaging in ohmic pulse-heating experiments. In addition to regular experiments at \(0.23\,\text {MPa}\), high-pressure experiments at static pressures between \(0.18\,\text {GPa}\) to \(0.30\,\text {GPa}\) were performed to increase the metals’ boiling point and thus determine density data at temperatures far exceeding the boiling temperature at atmospheric pressure. By this means, the experimentally accessible liquid range could be extended by roughly \(2000\,\text {K}\) (Ir) and \(6000\,\text {K}\) (Re) compared to data reported in the literature. In a second step, the experimental data were used to estimate critical temperature, critical density, and the complete phase diagram in the density–temperature plane. A comprehensive comparison with literature data was conducted.

中文翻译：

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液态铱和R从熔化到临界点的密度

通过欧姆脉冲加热实验中的阴影成像，确定了液态铱（Ir）和rh（Re）的密度随温度的变化。除了在\（0.23 \，\ text {Gpa} \）下进行常规实验外，在\（0.18 \，\ text {GPa} \）到\（0.30 \，\ text {GPa}之间的静态压力下进行高压实验\）进行，以增加金属沸点并由此确定的密度数据在温度远远超过在大气压力下的沸腾温度。通过这种方式，实验上可达到的液体范围可以扩大\（2000 \，\ text {K} \）（Ir）和\（6000 \，\ text {K} \）（Re）与文献报道的数据相比。第二步，将实验数据用于估算临界温度，临界密度以及密度-温度平面中的完整相图。与文献数据进行了全面比较。