Magnetic and structuralα−εphase transition in Fe monitored by x-ray emission spectroscopy

The iron structural and magnetic transition between the magnetic (bcc-$\ensuremath{\alpha})$ and the nonmagnetic (hcp-$\ensuremath{\epsilon})$ phases has been studied monitoring the pressure dependence of the Fe-$K\ensuremath{\beta}$ fluorescence line excited with monochromatic synchrotron radiation. The relative intensity of the two multiplets shows an S-shaped pressure curve with flex point at the known transition pressure of 130 kbar. The S width of $\ensuremath{\approx}30$ kbar also coincides with the one determined in structural determinations, and in magnetism studies using M\"ossbauer techniques. This shows how the x-ray emission method can be used to probe the local magnetic properties of atoms under extreme thermodynamic conditions.