Pressure induced magnetic transition in siderite FeCO3 studied by x-ray emission spectroscopy

We have investigated the magnetic state of iron in siderite FeCO3 under high pressure using K beta x-ray emission spectroscopy. Pressure induced changes in the shape of the iron K beta emission lines indicate that the iron ground state changes from a low pressure magnetic state to a high pressure non-magnetic state. This transition takes place roughly at 50 GPa. This conclusion is supported by charge transfer multiplet calculations of the iron K beta emission line.