Magnetic and structural α-ε phase transition in Fe monitored by x-ray emission spectroscopy

The iron structural and magnetic transition between the magnetic (bcc-alpha) and the nonmagnetic (hcp-epsilon) phases has been studied monitoring the pressure dependence of the Fe-K 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 approximate to 30 kbar also coincides with the one determined in structural determinations, and in magnetism studies using Mossbauer techniques. This shows how the x-ray emission method can be used to probe the local magnetic properties of atoms under extreme thermodynamic conditions. [S0163-1829(99)03745-5].