High-Pressure Mössbauer Studies of Magnetism in ScFe2 and Sc0.4Ti0.6Fe2 Laves Phases |
| K. Rupprecht, J. Lu, G. Wortmann Physics Department, University of Paderborn, 33095 Paderborn, Germany J. Przewo¼nik and J. ¯ukrowski University of Mining and Metallurgy, Al. Mickiewicza 30, 30-059 Kraków, Poland |
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| We report on 57Fe-Mössbauer studies of the magnetic properties in ScFe2 and Sc0.4Ti0.6Fe2 performed as a function of pressure and temperature. Both systems crystallize in the C14-type Laves phase structure with two different Fe sites 6h and 2a. The ferromagnetic properties of ScFe2 (TC=540 K at ambient pressure) change around 30 GPa to antiferromagnetic order of the 6h sites with non-magnetic 2a sites. The ordering temperature is lowered to TN=300 K at 51 GPa. This pressure-dependent behaviour of ScFe2 resembles that observed within the Sc1-xTixFe2 series as a function of x. In ferromagnetic Sc0.4Ti0.6Fe2 we observe, as a function of temperature and of pressure, an abrupt high-moment to low-moment transition of the Fe band moments of the 6h sites, accompanied by a rearrangement of the spin directions. In both systems the decrease in the Fe moments is accompanied by a strong increase in the volume coefficient of the isomer shift, originating from a reduced s-electron shielding capability of the d-electrons in the low-moment state. |
| DOI: 10.12693/APhysPolA.100.789 PACS numbers: 75.50.Bb, 76.80.+y |