Magnetic and structural transitions in magnetocaloric Mn(Co1-xNix)Ge alloys
dc.contributor.author | Ren, QY | en_AU |
dc.contributor.author | Hutchison, WD | en_AU |
dc.contributor.author | Wang, JL | en_AU |
dc.contributor.author | Studer, AJ | en_AU |
dc.contributor.author | Cadogan, JM | en_AU |
dc.contributor.author | Campbell, SJ | en_AU |
dc.date.accessioned | 2021-12-17T00:28:00Z | en_AU |
dc.date.available | 2021-12-17T00:28:00Z | en_AU |
dc.date.issued | 2017-02-01 | en_AU |
dc.date.statistics | 2021-09-24 | en_AU |
dc.description.abstract | The magnetocaloric effect (MCE) - a significant temperature change due to the entropy change around magnetic transitions in materials driven by magnetisation or demagnetisation - has emerged as an increasingly important topic in condensed matter physics in the past two decades. A direct (positive) MCE occurs around a magnetic transition from ferromagnetism (FM) to paramagnetism (PM), while an inverse (negative) MCE is obtained around a magnetic transition from antiferromagnetism (AFM) to FM. If such magnetic transitions couple with a structural transition, a first-order magneto-structural transition can form and hence strengthen the MCE. In this work, the magnetic and structural transitions have been tuned by substitution of Ni for Co in MnCoGe. The Mn(Co1-xNix)Ge samples (x = 0.14 - 1.00) were studied by magnetisation, x-ray and neutron powder diffraction measurements over the temperature range 5 - 450 K. Mn(Co1-xNix)Ge alloys have an orthorhombic (Orth) TiNiSi-type structure (Pnma) at low temperature with transformation to a hexagonal (Hex) Ni2In-type structure (P63/mmc) at the martensitic transformation temperature TM. The increase of the Ni content changes the orthorhombic phase from FM (x < 0.55) to spiral-AFM (x ≥ 0.55). In addition, the transformation temperature TM for the reverse martensitic transformation - from orthorhombic to hexagonal - decreases with Ni content x when x < 0.55 and then increases when x ≥ 0.55. The adjustment of TM leads to the occurrences of first-order FM-Orth/PM-Hex magneto-structural transitions and large values of the direct MCE in the samples with ~0.20 < x < ~0.60. Moreover, the spiral-AFM/FM magnetic transitions in the orthorhombic phase for samples with ~0.55 < x < ~0.75 result in an inverse MCE. | en_AU |
dc.identifier.citation | Ren, Q. Y., Hutchison, W. D., Wang, J. L., Studer, A. J., Cadogan, J. M., & Campbell, S. J. (2017). Magnetic and structural transitions in magnetocaloric Mn(Co1-xNix)Ge alloys. Paper presented to the 41st Annual Condensed Matter and Materials Meeting, Charles Sturt University, Wagga Wagga, NSW, Australia,31st January - 3rd February 2017, (pp. 36). Retrieved from: https://physics.org.au/wp-content/uploads/cmm/2017/Wagga_2017_Conference_Handbook.pdf | en_AU |
dc.identifier.conferenceenddate | 3 February 2017 | en_AU |
dc.identifier.conferencename | Australian and New Zealand Institutes of Physics 41st Annual Condensed Matter and Materials Meeting | en_AU |
dc.identifier.conferenceplace | Wagga Wagga, NSW | en_AU |
dc.identifier.conferencestartdate | 31 January 2017 | en_AU |
dc.identifier.other | WA1 | en_AU |
dc.identifier.pagination | 36 | en_AU |
dc.identifier.uri | https://physics.org.au/wp-content/uploads/cmm/2017/Wagga_2017_Conference_Handbook.pdf | en_AU |
dc.identifier.uri | https://apo.ansto.gov.au/dspace/handle/10238/12525 | en_AU |
dc.language.iso | en | en_AU |
dc.publisher | Australian Institute of Physics | en_AU |
dc.subject | Coherent scattering | en_AU |
dc.subject | Diffraction | en_AU |
dc.subject | Elements | en_AU |
dc.subject | Metals | en_AU |
dc.subject | Physical properties | en_AU |
dc.subject | Scattering | en_AU |
dc.subject | Thermodynamic properties | en_AU |
dc.subject | Transition elements | en_AU |
dc.subject | Magneto-thermal effects | en_AU |
dc.title | Magnetic and structural transitions in magnetocaloric Mn(Co1-xNix)Ge alloys | en_AU |
dc.type | Conference Presentation | en_AU |