Shape-anisotropic heterogeneous nucleation and magnetic Gibbs-Thomson effect in itinerant-electron metamagnetic transition of La(Fe0.88Si0.12)13 magnetocaloric compound

Macroscopic anisotropy of spatial selectivity in magnetic nucleation and growth was clarified for itinerant-electron metamagnetic transition of La(Fe0.88Si0.12)(13) by the time-dependent Ginzburg-Landau model combined with the Maxwell electromagnetic equation. Spontaneous generation of voltage supports symmetric growth in the longitudinal direction of the specimen as predicted by the simulation. The difference between nucleation-growth behaviors in thermally induced transition and those in field-induced transition is also elucidated. Electrical resistivity measurements also detect anisotropic growth of the induced phase. These results imply that the magnetic-dipole version of Gibbs-Thomson effect governs growth behavior. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789902]