This paper explains the effect of structural behaviour and electrical properties of cubic NaZn13-type La(FeSi)13 compounds annealed at different high temperatures from 1000ºC to 1200ºC. The Raman spectroscopy measurement revealed a different level of coexistence of La(FeSi)13-type phase and α-Fe in 1000ºC, 1100ºC and 1200ºC annealed samples. The different level coexistence of the phases suggested that the samples show a significant phase change with different annealing temperature. This finding has also supported by impedance analyzer measurement, where the pattern shows that the 1000ºC and 1100ºC samples have similar behaviour waveform pattern compared to the 1200ºC. Also, the impedance pattern clearly shows that the propagation of the signal for the 1000ºC and 1100ºC before it arrives in the conductor state (R=0.00) has high resistive values compared to 1200ºC annealed samples. Further investigation on the electrical properties were done with the conductivity and tan delt
Since the discovery of magnetocaloric effect (MCE), numbers of method in producing magnetocaloric materials has been studied. Among those methods, ball milling has been shown as a very versatile technique with several advantages compared to other preparation methods. In this work, the effect of ball milling preparation technique on the phase structural behaviour and electrical properties of MnCoGe alloys has been analysed. The changes in the structural behaviour have been studied by X-ray powder diffraction (XRD) and Raman Spectroscopy. The results suggest that the samples show significant structural changes with different method of ball milling running time. This finding has also been supported by electrical properties where the measurement found that the frequency also plays important role in the structure changes. The absolute impedance value,|Z| (Ω) suggest that structure start to change at initial frequency structure of hexagonal at point 3.22 Ω and 44.1 MHz region. The permitti
The critical behaviour associated with the field-induced martensitic transformation heav-ily relies on the vacancy and transition of the magnetic phase in MnCoGe based-compounds. Due to this revelation, an intensive investigation was brought forth to study the substitution of Ge (atomic radius = 1.23 Å) by Al (atomic radius = 1.43 Å) in MnCoGe0.97Al0.03 alloy compound. The room-temperature X-ray diffraction indicated that the reflections were identified with the ortho-rhombic structure (TiNiSi-type, space group Pnma) and minor hexagonal structure (Ni2In-type, space group P63/mmc). The substitution of Al in the supersession of Ge transmuted the crystal structure from TiNiSi-type to Ni2In-type structure. The MnCoGe0.97Al0.03 compound’s magnetism was driven by interactions that are long in range, as indicated by the study of the critical behaviour in the proximity of TC. The magnetic measurement and neutron diffraction revealed that the structural transition took place with the decrea