High-pressure Mössbauer spectroscopy using synchrotron radiation and radioactive sources

Research paper by Saburo Nasu

Indexed on: 01 Nov '00Published on: 01 Nov '00Published in: Hyperfine Interactions


A high-pressure 57Fe Mössbauer study of SrFeO3 up to 74 GPa has been performed with diamond-anvil-cell (DAC) using synchrotron radiation and a radioactive point source of 57Co in Rh. SrFeO3 is known as a typical cubic perovskite with a high-valence state of Fe4+ and shows metallic conductivity at 0.1 MPa down to 4.2 K. Applying an external high pressure, SrFeO3 has not shown any structural transformation up to 74 GPa keeping an Fe4+ state but the Néel temperature increases up to 300 K at 18 GPa. The external high pressure may induce the ferromagnetism in SrFeO3 by a decrease of the interatomic distance of Fe or an increase of the d-band width. 57Fe Mössbauer measurements under externally applied longitudinal magnetic field using radioactive 57Co in Rh source and also nuclear forward scattering measurements with a linearly polarized synchrotron radiation under external magnetic field indicate the existence of the pressure induced ferromagnetism in SrFeO3. In this work we compare high-pressure Mössbauer spectroscopy using synchrotron and radioactive sources and summarize the advantages and disadvantages of each method.