Thermodynamic-state and kinetic-process dependent dual ferromagnetic states in high-Si content FeMn(PSi) alloys
2015 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 118, no 21, 213903Article in journal (Refereed) PublishedText
We have found that thermodynamic state and kinetic process co-determine the dual ferromagnetic (FM) orders in high-Si content FeMnP1-xSix (0.25 < x < 0.5). Alloys undergoing high temperature annealing and quenching process prefer a high magnetic moment FM state in a chemically partial disordered structure with low c/a ratio. This mechanism is suggested to be responsible for the often discussed virgin effect as well. A chemically ordered structure obtained by a slow cooling process from a relatively low annealing temperature and the increase in Si content stabilize a metastable lattice with high c/a ratio and FM order with low magnetic moment. The non-simultaneity of the magnetic and structural transitions can be responsible for the occurrence of FM state in the high c/a range. Thus, a c/a ratio that changes from high to low is physically plausible to stabilize the metastable FM order at low temperature. Our theoretical observations indicate that suitable thermodynamic state and kinetic diffusion process is crucial for optimizing magnetocaloric properties and exploring feasible magnetocaloric materials.
Place, publisher, year, edition, pages
2015. Vol. 118, no 21, 213903
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-280933DOI: 10.1063/1.4936835ISI: 000369918100011OAI: oai:DiVA.org:uu-280933DiVA: diva2:912258
FunderSwedish Research CouncilSwedish Foundation for Strategic Research StandUpKnut and Alice Wallenberg Foundation