Structural Behaviour and Electrical Properties of a Ball Milled MnCoGe Compounds

Abstract

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 permittivity and dielectric loss (tan delta) graph that corresponds to a frequency (Hz) up to 100 kHz shown that the 2-hours milling time MnCoGe compound has the lowest permittivity value which make it had lower energy and required more frequency to react.