Ferromagnetism of (ScCa)Co2 Laves phase compound synthesized under high pressure

The appearance of ferromagnetism in (Sc0.85Ca0.15)Co2 Laves phase synthesized under high pressure of 6 GPa was confirmed. A magnetically homogeneous state was achieved by applying pressure of 6 GPa in 1373 K for 48 h. This is the first study that confirmed a stable ferromagnetic state in exchange-enhanced Pauli paramagnet ScCo2-based compound system. The quantities of pressure P and magnetization M dependence of the Curie temperature TC, dln TC/dP and (dln TC/dP)/(dln M/dP) = dln TC/dln M for (Sc0.85Ca0.15)Co2 are smaller than those for Lu(Co1 − xAlx)2 compounds, and accordingly the magnetic moment of (Sc0.85Ca0.15)Co2 is stiffer against pressure. The ratio of the spin wave stiffness constant Ds to TC, Ds/TC, in (Sc0.85Ca0.15)Co2 is smaller than that of Lu(Co1 − xAlx)2, implying that the spin wave in (Sc0.85Ca0.15)Co2 spread over wider wavevector space.