A review is given of experimental and calculated data on the viscosity of iron-based melts on the melting curve. The interest in these data originates in the division of opinion on whether viscosity increases rather moderately or considerably in the high-pressure range. This disagreement is especially pronounced in the interpretation of the values of molten iron and its compounds in the environment of the earth’s outer core. The conclusion on a substantial rise in viscosity mostly follows from the universal law, proposed by Brazhkin and Lyapin [1], of viscosity changing along the metal melting curve in the high-pressure range. The review analyzes available experimental and computational data, including the most recent ones. Data on viscosity of metals under shock wave compression in the megabar pressure range are also discussed. It is shown that data on viscosity of metal melts point to a small increase of viscosity on the melting curve. Specifics are discussed of the phase diagram of iron made more complex by the presence of several phase transitions and by the uncertainty in the position of the melting curve in the high-pressure range. Inaccuracies that arise in extrapolating the results of viscosity measurements to the pressure range corresponding to the earth’s core environment are pointed out.

PACS: 62.50.+p, 66.20.+d, 81.30.Bx, 91.35.−x (all) DOI: 10.1070/PU2004v047n07ABEH001746 URL: https://ufn.ru/en/articles/2004/7/b/ 000225027900002 2004PhyU...47..671M Citation: Mineev V N, Funtikov A I "Viscosity measurements on metal melts at high pressure and viscosity calculations for the earth's core" Phys. Usp. 47 671–686 (2004) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Оригинал: Минеев В Н, Фунтиков А И «Об измерении вязкости расплавов металлов при высоких давлениях и расчетах вязкости применительно к ядру Земли» УФН 174 727–742 (2004); DOI: 10.3367/UFNr.0174.200407b.0727