The magneto-structural transition in magnetocaloric Mn1-xFexCoGe
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Date
2015-02-03
Journal Title
Journal ISSN
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Publisher
Australian Institute of Physics
Abstract
Magnetic refrigeration techniques based on the magnetocaloric effect are considered an increasingly viable alternative to conventional gas-compression refrigerant, particularly with energy-saving and environmental aspects in mind. Following the discovery of a large magnetocaloric effect in Gd5Si2Ge2, researchers have shifted their attention to investigation of materials exhibiting magneto-structural transitions where large magnetic entropy changes are expected. MnCoGe-based compounds are promising materials for the exploration of large magnetocaloric effects. They are relatively cheap (no rare earth elements) and, importantly, allow an appropriate temperature window (275 – 345 K) around room temperature in which the magneto-structural transition may be positioned. It has been established that Fe is a suitable substitute for Mn to ‘tune’ the structural transition temperature and hence obtain a magneto-structural transition. Here we present the results of a detailed investigation of the structural and magnetic properties and magnetocaloric effect for a range of as-prepared Mn1-xFexCoGe alloys (x = 0.01, 0.02, 0.03 and 0.04) using temperature variable x-ray diffraction (20 – 310 K), neutron diffraction (5 – 450 K) and physical properties measurement system (PPMS, 5 – 300 K). Particular attention will focus on analysis of neutron diffraction data for Mn0.98Fe0.02CoGe and the nature of the magnetic phase transition in Mn0.98Fe0.02CoGe.
Description
Keywords
Cobalt alloys, Cooling systems, Energy conservation, Entropy, Germanium alloys, Magnetic fields, Magnetic refrigerators, Manganese alloys, Neutron diffraction, Temperature dependence, X-ray diffraction
Citation
Ren, Q. Y., Hutchison, W. D., Wang, J., L., Studer, A. J., Md Din, M. F., Muñoz Pérez, S., Cadogan, J. M., & Campbell, S. J. (2015). The magneto-structural transition in magnetocaloric Mn1-xFexCoGe. Paper presented at the 39th Annual Condensed Matter and Materials Meeting, Charles Sturt University, Wagga Wagga, NSW, 3 February 2015 - 6 February 2015, (pp. 59). Retrieved from: https://physics.org.au/wp-content/uploads/cmm/2015/Wagga2015_10_Handbook.pdf