The thermally induced first-order magnetic phase transition in a La(Fe0.90Si0.10)13 compound has been observed at the Curie temperature TC by using Lorentz microscopy in the Fresnel mode. On heating the specimen, the magnetic domains instantly disappeared at TC due to the nature of the first-order phase transition. The coexistence of the ferromagnetic and paramagnetic phases was observed at TC. The magnetic domain structure below TC was unchanged by repeating the thermal cycles. This fact implies that the phase transition during thermal cycles does not induce any lattice defects that degrade the magnetocaloric effect.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics