Effects of heat treatments on magneto-structural phase transitions in MnNiSi-FeCoGe alloys
| Autor: | Igor Dubenko, Jing-Han Chen, David P. Young, Tej Poudel Chhetri, Naushad Ali, Shane Stadler, Ahmad Us Saleheen |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Quenching Austenite Materials science Mechanical Engineering Transition temperature Hydrostatic pressure Metals and Alloys Thermodynamics 02 engineering and technology General Chemistry Atmospheric temperature range 021001 nanoscience & nanotechnology 01 natural sciences Isothermal process Mechanics of Materials Martensite 0103 physical sciences Materials Chemistry Magnetic refrigeration 0210 nano-technology |
| Zdroj: | Intermetallics. 112:106547 |
| ISSN: | 0966-9795 |
| DOI: | 10.1016/j.intermet.2019.106547 |
| Popis: | A first-order magneto-structural transition from a ferromagnetic orthorhombic TiNiSi-type martensite phase to a paramagnetic hexagonal Ni2In-type austenite phase was observed in (MnNiSi)0.62(FeCoGe)0.38. In this work, we demonstrate that the first-order magneto-structural transition temperature for a given composition is tunable over a wide temperature range through heat treatment and hydrostatic pressure application. The first-order transition temperature decreased by over 150 K as the annealing/quenching temperature went from 700 to 1050 ° C . The largest maximum magnetic-field-induced isothermal entropy change with μ 0 Δ H = 7 T reached −36.2 J/kg-K for the sample quenched at 700 ° C , and the largest effective refrigeration capacity reached 344.5 J/kg for the sample quenched at 800 ° C . Similar to the influence of annealing temperatures, the first-order martensitic transition temperatures decreased as the applied hydrostatic pressure increased until they were completely converted to second order. Our results suggest that the class of MnNiSi-based alloys is a promising platform for tailoring working temperature ranges and associated magnetocaloric effects through heat treatment or application of hydrostatic pressure. |
| Databáze: | OpenAIRE |
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